According to the present invention, a solidified detergent composition is provided. The solidified detergent composition is characterized by having a reduced-pressure dried substance obtained by reduced-pressure drying a solution of (a) a silicon-containing compound with the addition of (b) at least one of surfactant to the silicon-containing compound, or a reduced-pressure dried substance obtained by reduced-pressure drying a solution of (a) a silicon-containing compound and (b) at least one of surfactant added to the resultant reduced-pressure dried substance, the silicon-containing compound being represented by the following general formula (1):(wherein R1 shows a hydrocarbon group having 6 or more carbon atom number, R2 and R3 show a lower hydrocarbon group which may be same or different each other, R4 shows a bivalent lower hydrocarbon group, R5, R6 and R7 show a lower alkyl group or lower alkoxy group which may be same or different each other, X shows a halogen ion or organic carbonyloxy ion) and the surfactant being selected from the group consisting of (b1) a cationic surfactant (but excluding the above silicon-containing compound) and (b2) a nonionic surfactant.
