To provide a two-agent mixing container capable of mixing a first agent and a second agent by turning a cap in one direction, opening a lid to be able to use a mixed agent in a container body, and allowing a user to easily discriminate whether or not any illegal action such as a tamper is executed.

The two-agent mixing container comprises: a container body accommodating the first agent; and a cap accommodating the second agent in an inner part consisting of an inner cap and an outer cap. The inner cap comprises a lower wall, a bottom wall, an inner cylinder, an upper wall and an outer cylinder. A distribution hole is cut in the bottom wall, a cutout is formed at the predetermined position of the outer periphery of the outer cylinder from an upper end of the outer cylinder. An engagement recess with an abutting surface part having an inclined surface therebelow is formed. The outer cap comprises: a top wall; an inner cylinder with an outer periphery thereof, being inserted in an inner periphery of the inner cylinder of the inner cap; and an outer cylinder. The inner cylinder is formed so that its lower end is abutted on an upper surface of the bottom wall, and an abutting rib to be engaged with the engagement recess of the outer cylinder of the inner cap is arranged on the inner periphery of the outer cylinder.