A continuous processing trap apparatus is capable of increasing the trapping efficiency while maintaining conductance required by a vacuum chamber. The trap apparatus includes an exhaust passage for evacuating a hermetically sealed chamber by a vacuum pump, a hermetically sealed trapping and regenerating casing extending across the exhaust passage and a regenerating passage adjacent to the exhaust passage, and a trap unit movably housed in the trapping and regenerating casing for selective movement between a trapping position connected to the exhaust passage and a regenerating position connected to the regenerating passage. The trap apparatus further includes valve bodies disposed one on each side of the trap unit and supporting seals on outer circumferential surfaces thereof for sealing the exhaust passage and the regenerating passage from each other, and a monitoring mechanism for monitoring whether the seals are functioning normally.