A discharge container comprising: a double-walled container body including an inner layer body which defines a containment space for a content and is deformable in a volume-reducing manner and an outer layer body surrounding the inner layer body; a discharge cap attached to a mouth of the double-walled container body; a valve member; and a valve retaining member; wherein the discharge cap includes an outer circumferential wall, a top wall integrally connected to the upper end of the outer circumferential wall, the top wall being provided with a discharge tube for a content, which tube forms a discharge outlet, wherein the valve member is retained in the discharge cap using the valve retaining member installed inside the discharge cap, wherein the valve member includes a cylindrical base portion, a ring-shaped flange portion provided inside the base portion, a cylindrical partition wall hanging down from the inner periphery of the flange portion, and a valve body provided on the partition wall with a hinge portion and having a single swing structure swung on the hinge portion, wherein the valve retaining member includes a partition wall portion placed to cover the upper opening of the inner layer body, and an outer tube portion standing from the outer periphery of the partition wall portion, wherein a tubular retainer tube is provided on the partition wall portion and an end portion of the retainer tube is provided with a ring wall shaped like a flange inclined radially inside, wherein an opening serving as a flow path of the content is formed in the ring wall, wherein the ring wall serves as a valve seat portion for the valve body and the outer peripheral portion of the valve body abuts the entire circumference of the upper surface of the ring wall to close the opening, wherein the partition wall is placed inside the retainer tube and defines a flow path of content from the containment space to the discharge outlet, wherein space inside the partition wall, rather on the discharge outlet side than on the valve body side serves as a liquid reservoir space where part of remaining content is stored after the discharge of the content, wherein the partition wall, the valve body, and the ring wall serve as a valve seat portion and form a check valve structure which allows a flow of the content from the containment space toward the discharge outlet and prevents backflow from the discharge outlet toward the containment space. a double-walled container body including an inner layer body which defines a containment space for a content and is deformable in a volume-reducing manner and an outer layer body surrounding the inner layer body; a discharge cap attached to a mouth of the double-walled container body; a valve member; and a valve retaining member; wherein the discharge cap includes an outer circumferential wall, a top wall integrally connected to the upper end of the outer circumferential wall, the top wall being provided with a discharge tube for a content, which tube forms a discharge outlet, wherein the valve member is retained in the discharge cap using the valve retaining member installed inside the discharge cap, wherein the valve member includes a cylindrical base portion, a ring-shaped flange portion provided inside the base portion, a cylindrical partition wall hanging down from the inner periphery of the flange portion, and a valve body provided on the partition wall with a hinge portion and having a single swing structure swung on the hinge portion, wherein the valve retaining member includes a partition wall portion placed to cover the upper opening of the inner layer body, and an outer tube portion standing from the outer periphery of the partition wall portion, wherein a tubular retainer tube is provided on the partition wall portion and an end portion of the retainer tube is provided with a ring wall shaped like a flange inclined radially inside, wherein an opening serving as a flow path of the content is formed in the ring wall, wherein the ring wall serves as a valve seat portion for the valve body and the outer peripheral portion of the valve body abuts the entire circumference of the upper surface of the ring wall to close the opening, wherein the partition wall is placed inside the retainer tube and defines a flow path of content from the containment space to the discharge outlet, wherein space inside the partition wall, rather on the discharge outlet side than on the valve body side serves as a liquid reservoir space where part of remaining content is stored after the discharge of the content, wherein the partition wall, the valve body, and the ring wall serve as a valve seat portion and form a check valve structure which allows a flow of the content from the containment space toward the discharge outlet and prevents backflow from the discharge outlet toward the containment space.