The Gamow-Teller transition strength B(GT) of 24Si was measured to investigate characteristic structure of proton-rich nuclei induced by a weakly-bound proton. By combining the results of the delayed γ-ray and proton measurements, the entire decay scheme of 24Si was reconstructed, then the B(GT) of 24Si was deduced. Focusing to the low-lying states, the B(GT) of 24Si to the 11+ and 12+ states in 24Al were smaller than that of the mirror nucleus 24Ne by 22 % and 10 %, respectively. The mirror asymmetry of B(GT) indicates the configuration change in the wave function. Through the comparison with theoretical shell-model calculations, it is implied that the configuration change is attributed to the lowering of the 1s 1/2 orbital. The applicability of the theoretical calculations was checked using overall B(GT) distribution.