<p>A fuse unit including a fuse element therein includes a first resin body and a second resin body. The second resin body is connected to the first resin body by a hinge portion and configured to be bended around the hinge portion with respect to the first resin body. A pair of first side walls and a pair of second side walls are provided on the first resin body and the second resin body respectively and extend in a direction intersecting an axis of the bending of the second resin body. A pair of engaging parts are provided at the lock arms provided at the first side walls respectively respectively, and each of which has first inclined face. A pair of engaged parts are provided at the second side walls respectively, and corresponds to the engaging parts respectively, and each of which has second inclined face configured to contact the first inclined face in surface contact in a state that the second resin body is bended. The first inclined face and the second inclined face are formed along a direction intersecting a direction of a reaction force by springback of the fuse element caused by the bending of the second resin body.</p>