A simulation gun, comprising: an electric mechanism, a cut-off device for the electric mechanism, and a piston cylinder mechanism having a movable portion, wherein the electric mechanism is configured to drive the movable portion of the piston cylinder mechanism in one direction such that pressure is accumulated in pressurization means, and wherein the pressurization means is released such that the piston cylinder mechanism is driven in a direction opposite to the one direction and compressed air for shooting a bullet is generated, wherein the cut-off device comprises: a switching mechanism that is configured to control a drive circuit of an electric motor of the simulation gun in order to select any one of a single shooting mode in which one bullet shooting is performed through one reciprocating operation in the piston cylinder mechanism, and a successive shooting mode in which a plurality of the bullet shootings are performed through a plurality of the reciprocating operations in the piston cylinder mechanism, wherein the switching mechanism includes at least a selector operating unit which is provided in order to select between the single shooting mode and the successive shooting mode, a switch configured to close the drive circuit in response to an operation of a trigger, characterized in that the switching mechanism further includes a cut-off member configured to engage with the movable portion being driven in the one direction and turns off the switch when the single shooting mode is selected, wherein an engagement location for the movable portion and the cut-off member in the piston cylinder mechanism is set in an end portion in a direction of a retracting operation of the movable portion, to prolong a time taken until the movable portion engages with the cut-off member after the movable portion starts to retract. an electric mechanism, a cut-off device for the electric mechanism, and a piston cylinder mechanism having a movable portion, wherein the electric mechanism is configured to drive the movable portion of the piston cylinder mechanism in one direction such that pressure is accumulated in pressurization means, and wherein the pressurization means is released such that the piston cylinder mechanism is driven in a direction opposite to the one direction and compressed air for shooting a bullet is generated, wherein the cut-off device comprises: a switching mechanism that is configured to control a drive circuit of an electric motor of the simulation gun in order to select any one of a single shooting mode in which one bullet shooting is performed through one reciprocating operation in the piston cylinder mechanism, and a successive shooting mode in which a plurality of the bullet shootings are performed through a plurality of the reciprocating operations in the piston cylinder mechanism, wherein the switching mechanism includes at least a selector operating unit which is provided in order to select between the single shooting mode and the successive shooting mode, a switch configured to close the drive circuit in response to an operation of a trigger, characterized in that the switching mechanism further includes a cut-off member configured to engage with the movable portion being driven in the one direction and turns off the switch when the single shooting mode is selected, wherein an engagement location for the movable portion and the cut-off member in the piston cylinder mechanism is set in an end portion in a direction of a retracting operation of the movable portion, to prolong a time taken until the movable portion engages with the cut-off member after the movable portion starts to retract. a switching mechanism that is configured to control a drive circuit of an electric motor of the simulation gun in order to select any one of a single shooting mode in which one bullet shooting is performed through one reciprocating operation in the piston cylinder mechanism, and a successive shooting mode in which a plurality of the bullet shootings are performed through a plurality of the reciprocating operations in the piston cylinder mechanism, wherein the switching mechanism includes at least a selector operating unit which is provided in order to select between the single shooting mode and the successive shooting mode, a switch configured to close the drive circuit in response to an operation of a trigger, characterized in that the switching mechanism further includes a cut-off member configured to engage with the movable portion being driven in the one direction and turns off the switch when the single shooting mode is selected, wherein an engagement location for the movable portion and the cut-off member in the piston cylinder mechanism is set in an end portion in a direction of a retracting operation of the movable portion, to prolong a time taken until the movable portion engages with the cut-off member after the movable portion starts to retract.