A seal affixing system comprising: a porous adsorption end effector having an adsorption face containing a plurality of adsorption pores to which seal (S) is to be adsorbed; a suction power generator configured to communicate with the adsorption pores and generate adsorption power of holding the seal (S) by the adsorption face ; and a controller configured to control the suction power generator in adsorbing the seal (S) by the porous adsorption end effector and affixing the seal (S) to an external target (T), wherein when a direction along a movement direction (X1) in which the porous adsorption end effector moves in affixing the seal (S) to the target (T) is referred to as a first direction (X), and a direction orthogonal to the first direction (X) is referred to as a second direction (Y), the adsorption pores are arranged plurally along the first direction (X) and the second direction (Y) 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 (X1), 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 (S) to the adsorption face is determined to be unnecessary as an operation of affixing the seal (S) to the target (T) progresses from a state where the seal (S) is adsorbed in the plurality of suction regions (A1, A2, A3), and determine that adsorption of the seal (S) 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 (S) is to be adsorbed; a suction power generator configured to communicate with the adsorption pores and generate adsorption power of holding the seal (S) by the adsorption face ; and a controller configured to control the suction power generator in adsorbing the seal (S) by the porous adsorption end effector and affixing the seal (S) to an external target (T), wherein when a direction along a movement direction (X1) in which the porous adsorption end effector moves in affixing the seal (S) to the target (T) is referred to as a first direction (X), and a direction orthogonal to the first direction (X) is referred to as a second direction (Y), the adsorption pores are arranged plurally along the first direction (X) and the second direction (Y) 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 (X1), 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 (S) to the adsorption face is determined to be unnecessary as an operation of affixing the seal (S) to the target (T) progresses from a state where the seal (S) is adsorbed in the plurality of suction regions (A1, A2, A3), and determine that adsorption of the seal (S) to the adsorption face is unnecessary when a suction pressure does not reach a specified value <EOS>