A seal affixing system comprising: a porous adsorption end effector having an adsorption face containing a plurality of adsorption pores to which seal is to be adsorbed; a suction power generator configured to communicate with the adsorption pores and generate adsorption power of holding the seal by the adsorption face; and a controller configured to control the suction power generator in adsorbing the seal by the porous adsorption end effector and affixing the seal to an external target, wherein when a direction along a movement direction in which the porous adsorption end effector moves in affixing the seal to the target is referred to as a first direction, and a direction orthogonal to the first direction is referred to as a second direction, the adsorption pores are arranged plurally along the first direction and the second direction on the adsorption face, the plurality of adsorption pores are sectioned into a plurality of suction regions (A1, A2, A3) containing a plurality of the adsorption pores from a downstream side to an upstream side along the movement direction, wherein the controller is configured to: control the suction power generator to individually suck the plurality of suction regions (A1, A2, A3); conduct a control of sequentially stopping suction of the suction regions (A1, A2, A3) for which adsorption of the seal to the adsorption face is determined to be unnecessary as an operation of affixing the seal to the target progresses from a state where the seal is adsorbed in the plurality of suction regions (A1, A2, A3), and determine that adsorption of the seal to the adsorption face is unnecessary when a suction pressure does not reach a specified value a porous adsorption end effector having an adsorption face containing a plurality of adsorption pores to which seal is to be adsorbed; a suction power generator configured to communicate with the adsorption pores and generate adsorption power of holding the seal by the adsorption face; and a controller configured to control the suction power generator in adsorbing the seal by the porous adsorption end effector and affixing the seal to an external target, wherein when a direction along a movement direction in which the porous adsorption end effector moves in affixing the seal to the target is referred to as a first direction, and a direction orthogonal to the first direction is referred to as a second direction, the adsorption pores are arranged plurally along the first direction and the second direction on the adsorption face, the plurality of adsorption pores are sectioned into a plurality of suction regions (A1, A2, A3) containing a plurality of the adsorption pores from a downstream side to an upstream side along the movement direction, control the suction power generator to individually suck the plurality of suction regions (A1, A2, A3); conduct a control of sequentially stopping suction of the suction regions (A1, A2, A3) for which adsorption of the seal to the adsorption face is determined to be unnecessary as an operation of affixing the seal to the target progresses from a state where the seal is adsorbed in the plurality of suction regions (A1, A2, A3), and determine that adsorption of the seal to the adsorption face is unnecessary when a suction pressure does not reach a specified value