Angle-resolved photoemission spectroscopy of Ca(Al0.5Si0.5)(2) (CaAlSi), which is a superconductor (transition temperature is 7.7 K) with the AlB2 structure, revealed that superconducting gaps on two Fermi surfaces (FSs) with three-dimensional character around Gamma(A) and M(L) in the Brillouin zone provide essentially the same superconducting gap value (similar to1.2 meV+/-0.2 meV). This is in contrast to the case of MgB2, in which different FSs exhibit different gap values. The reduced gap value 2Delta(0)/k(B)T(c) of similar to4.2+/-0.2 classifies CaAlSi as a moderately strong-coupling superconductor.