To provide a vaporized fuel processing device capable of suppressing heating to an adsorbent and promoting segregation of vaporized fuel from the adsorbent.

The vaporized fuel processing device 1 has an adsorption chamber 6 filled with the adsorbent 6a to perform adsorption and segregation of the fuel components, and has a light source 17 to cast light including infrared ray to at least a part the adsorbent 6a, wherein the infrared ray have a wavelength which is absorbed by an expansion-contraction vibration or angle varying vibration of a bond present in at least one molecule in the fuel component.