Résumé dans la langue de publication Disclosed is a protective case for protecting a portable electronic device against moisture and dust so that the device can be carried anywhere. The protective case has an upper case and a lower case which, by being abutted against each other, form a closed space in a interior of which the portable electronic device (100) is capable of being accommodated. Provided in at least one of the cases is a through-hole at a position opposing an operating element of the portable electronic device accommodated inside the space. The through-hole is closed by a closure member (167) comprising an elastic material and having a push-button (165) that is capable of pushing the operating element of the portable electronic device from the outside. Furthermore, the abutting portion of each case is sealed by a sealing member comprising an elastic material, whereby moisture and dust are positively prevented from penetrating the interior.