Extensive studies on the ferromagnetic semiconductor GaMnAs in the last decade have revealed a variety of unique features induced by the combination of its magnetic and semiconducting properties. However, complete understanding of the band structure of GaMnAs has not been achieved yet. Especially, there has been a hot dispute on the Fermi level (<I>E</I><SUB>F</SUB>) position of GaMnAs. Resonant tunneling spectroscopy is a very powerful method for investigating the band structure, because the observed resonant levels contain a lot of information, such as the effective mass, band offset, and <I>E</I><SUB>F</SUB> [1,2]. Here, using a precise etching technique and resonant tunneling spectroscopy, applied to a variety of surface GaMnAs layers, we show the universal valence-band (VB) picture of GaMnAs. We find that <I>E</I><SUB>F</SUB> exists in the bandgap for any of the GaMnAs samples with Mn concentrations ranging from 6 to 15%, and that the VB structure of GaAs is almost perfectly maintained and does not merge with the impurity band. Furthermore, the exchange splitting of the VB, which has been generally thought to be important for the appearance of ferromagnetism, is found to be very small (only several meV), even in GaMnAs with a high Curie temperature (154 K). Our new findings are largely different from the conventional understanding of the ferromagnetic semiconductors . To investigate the VB structure, we used heterostructures comprising Ga<SUB>1-<I>x</I></SUB>Mn<SUB><I>x</I></SUB>As (4-20 nm)/ AlAs (5 nm)/ GaAs:Be (Be: 1×10<SUP>18</SUP> cm<SUP>-3</SUP>)/ p<SUP>+</SUP>GaAs(001). After the growth, we fabricated mesa diodes with various GaMnAs thicknesses (<I>d</I> = 0-20 nm) in the same sample wafer by carefully controlling the etching time for the GaMnAs layer. Since the Schottky barrier is formed at the surface of the GaMnAs layer due to the <I>E</I><SUB>F</SUB> pinning, the VB holes are confined by the Schottky barrier and the AlAs barrier. Thus, resonant levels are formed in the GaMnAs layer. With increasing <I>d</I>, the resonant energies approach the VB top in the bulk GaMnAs. In all the samples examined here, clear oscillations of the <I>d</I><SUP>2</SUP><I>I</I>/<I>dV</I><SUP>2</SUP>-<I>V</I> characteristics due to resonant tunneling were observed. The resonant levels were converged at a certain negative bias voltage with increasing <I>d</I>, which indicates that <I>E</I><SUB>F</SUB> exists in the bandgap. We found that these resonant levels are well reproduced by the calculated ones when assuming the same effective masses of holes as those in GaAs. This work was partly supported by Grant-in-Aids for Scientific Research, the Special Coordination Programs for Promoting Science and Technology, and FIRST Program of JSPS.