A compound container has a container main body forming a first accommodation chamber, an auxiliary container forming a second accommodation chamber, a mounting part on which the auxiliary container is mounted in the container main body, a cutting part which cuts a second accommodation chamber partition wall which partitions a part of the second accommodation chamber formed in the auxiliary container, a contents outlet port in the container main body, and an opening pouring element mounted on the contents outlet port and having another cutting part which cuts a first accommodation chamber partition wall which partitions a part of the first accommodation chamber formed in the container main body.