A container that comprises a cylindrical container body, and a lid member coupled to the container body by a hinge so as to be openable/closable relative to an opening portion of the container body, wherein: the opening portion of the container body has an outer peripheral surface, with at least a part of which being formed with a container body rib; the lid member is formed with a sidewall at a position of externally contacting the opening portion, in a state where the lid member is closed; the sidewall has an inner side surface provided with a lid rib which the container body rib contacts and slides over in opening/closing the lid member; the lid member is further formed with an inner ring at a position of internally contacting the opening portion, in a state where the lid member is closed; the opening portion of the container body has an inner diameter at least in a container body rib portion extending from a position where the container body rib is formed to an edge of the opening portion, the inner diameter being larger than that in the rest of the opening portion, and the inner ring has an outer diameter being smaller than the inner diameter at the container body rib portion such that a first gap is formed between the container body rib portion and the inner ring in a state in which the lid member is closed, the inner side surface of the sidewall has a part that is closer to the lid member with reference to the lid rib, the part having an inner diameter larger than an outer diameter of the container body rib to provide a second gap between itself and the container body rib in closing the lid member and in a state in which the lid member is closed, and in closing the lid member, the opening portion of the container body, the sidewall and the inner ring are configured in such a way that, before the container body rib contacts and slides over the lid rib, no other part of the opening portion than the container body rib comes into contact with the lid member because of the first gap, the container being characterized in that the opening portion of the container body, the sidewall and the inner ring are configured in such a way that the inner ring comes into contact with an inner peripheral surface of the opening portion after the container body rib has contacted and slid over the lid rib and passed a peak portion of the lid rib in the closing motion of the lid member. the opening portion of the container body has an outer peripheral surface, with at least a part of which being formed with a container body rib; the lid member is formed with a sidewall at a position of externally contacting the opening portion, in a state where the lid member is closed; the sidewall has an inner side surface provided with a lid rib which the container body rib contacts and slides over in opening/closing the lid member; the lid member is further formed with an inner ring at a position of internally contacting the opening portion, in a state where the lid member is closed; the opening portion of the container body has an inner diameter at least in a container body rib portion extending from a position where the container body rib is formed to an edge of the opening portion, the inner diameter being larger than that in the rest of the opening portion, and the inner ring has an outer diameter being smaller than the inner diameter at the container body rib portion such that a first gap is formed between the container body rib portion and the inner ring in a state in which the lid member is closed, the inner side surface of the sidewall has a part that is closer to the lid member with reference to the lid rib, the part having an inner diameter larger than an outer diameter of the container body rib to provide a second gap between itself and the container body rib in closing the lid member and in a state in which the lid member is closed, and in closing the lid member, the opening portion of the container body, the sidewall and the inner ring are configured in such a way that, before the container body rib contacts and slides over the lid rib, no other part of the opening portion than the container body rib comes into contact with the lid member because of the first gap, the container being characterized in that the opening portion of the container body, the sidewall and the inner ring are configured in such a way that the inner ring comes into contact with an inner peripheral surface of the opening portion after the container body rib has contacted and slid over the lid rib and passed a peak portion of the lid rib in the closing motion of the lid member.