An evaporated fuel processing device may include a flow passage through which evaporated fuel generated in a fuel tank flows; a first adsorbent constituted of activated carbon and arranged in the flow passage for adsorbing the evaporated fuel flowing in the flow passage; and a second adsorbent constituted of a porous metal complex and arranged in the flow passage on a downstream side of the first adsorbent for adsorbing the evaporated fuel having passed through the first adsorbent and flowing in the flow passage on the downstream side of the first adsorbent.