Provided is a two-component mixing container in which a piston member may be capable of a rotation motion operation and a linear motion operation without the need for a complex guide groove. Two or more spring structure portions are provided at the piston member. The two or more spring structure portions impart a pressing force on an inner wall surface of the third cylindrical portion. Two or more fitting grooves are formed in the third cylindrical portion. In this fitting state, the piston member and a second-component containing member rotate together without contact portions getting out of the fitting grooves. When a force of a predetermined level or higher toward a third bottom wall portion is applied to an operating rod portion with a second-component containing chamber and a mixing chamber being communicable with each other, the contact portions get out of the fitting grooves.