An explosion-proof apparatus includes a stopper having a hollow cylindrical shape that is open at a first side and closed at a second side, and configured to be combined with an electrolytic condenser to surround an explosion-proof face of the electrolytic condenser and a lateral side connected to the explosion-proof face, through the first side, and a holder provided on the stopper to support the stopper. The first side of the stopper is separated from the explosion-proof face of the electrolytic condenser, a lateral side of the stopper has a stepped structure in which a periphery of a first region connecting to the first side is larger than a periphery of a second region connecting to the second side, and the holder is mounted on the stopper to surround at least part of the periphery of the second region of the stopper.