A delaminatable container, comprising: a container body having an outer shell and an inner bag, the inner bag delaminating from the outer shell with a decrease in contents to be shrunk; and a valve member regulating entrance and exit of air between an external space of the container body and an intermediate space between the outer shell and the inner bag, wherein the container body includes a storage portion to store the contents and a mouth to discharge the contents from the storage portion, the outer shell includes a fresh air inlet communicating the intermediate space with the external space in the storage portion, the valve member includes a tube having a cavity provided to communicate the external space with the intermediate space and a mobile part having a spherical shape and being movably stored in the cavity, the tube includes a stem disposed in the fresh air inlet and a locking portion provided on an external space side at the stem and preventing entrance of the tube to the intermediate space, the stem has a tapered shape towards an intermediate space side and has an outer circumferential surface closely contacting to an edge of the fresh air inlet, thereby mounting the tube to the container body, the tube has a stopper to lock the mobile part with respect to movement of the mobile part from the intermediate space side towards the external space side, the stopper being provided on a surface surrounding the cavity, and the stopper is configured to block air communication through the cavity when the mobile part abuts on the stopper, the tube has a bottom or a projection (5e3) to lock the mobile part with respect to movement of the mobile part from the external space side towards the intermediate space side, the bottom or the projection (5e3) is provided on the intermediate space side of the cavity with respect of the stopper. a container body having an outer shell and an inner bag, the inner bag delaminating from the outer shell with a decrease in contents to be shrunk; and a valve member regulating entrance and exit of air between an external space of the container body and an intermediate space between the outer shell and the inner bag, wherein the container body includes a storage portion to store the contents and a mouth to discharge the contents from the storage portion, the outer shell includes a fresh air inlet communicating the intermediate space with the external space in the storage portion, the valve member includes a tube having a cavity provided to communicate the external space with the intermediate space and a mobile part having a spherical shape and being movably stored in the cavity, the tube includes a stem disposed in the fresh air inlet and a locking portion provided on an external space side at the stem and preventing entrance of the tube to the intermediate space, the stem has a tapered shape towards an intermediate space side and has an outer circumferential surface closely contacting to an edge of the fresh air inlet, thereby mounting the tube to the container body, the tube has a stopper to lock the mobile part with respect to movement of the mobile part from the intermediate space side towards the external space side, the stopper being provided on a surface surrounding the cavity, and the stopper is configured to block air communication through the cavity when the mobile part abuts on the stopper, the tube has a bottom or a projection (5e3) to lock the mobile part with respect to movement of the mobile part from the external space side towards the intermediate space side, the bottom or the projection (5e3) is provided on the intermediate space side of the cavity with respect of the stopper.