Vaporized fuel treatment apparatus

A vaporized fuel treatment apparatus having comprising a first adsorbent having a honeycomb structure capable of adsorbing and desorbing vapor contained in fuel evaporation gas, a case configured to house the first adsorbent therein, and a holding device configured to elastically hold the first adsorbent within the case. The first adsorbent has a circumferential surface and at least one end surface intersecting with the circumferential surface at a corner portion. The holding device comprises a holding member having a first portion and a second portion configured to contact with the circumferential surface and the at least one end surface, respectively. The holding member does not contact with the corner portion of the first adsorbent. The vaporized fuel treatment apparatus can include a sealed container disposed in a canister for controlling temperature alteration in the canister.