A solid germicidal composition containing a compound of the formula (I), a carbonate compound and an organic acid with a solubility in water at 20° C. of 0.25 to 35%:wherein, R1 represents a saturated linear alkyl group having 1 to 3 carbon atoms, R2 represents a saturated linear alkyl group having 8 to 12 carbon atoms, X− represents a halogen ion and Y represents a saturated linear alkylene group having 8 to 12 carbon atoms is disclosed. A method for disinfecting an object, which comprises contacting an aqueous solution of the composition with the object, is also disclosed. The solid germicidal composition is effective against various microorganisms and hardly causes development of resistance to the composition itself in microorganisms even when the composition is continually or continuously used.
