A linear reciprocating-motion apparatus comprising: a housing; a movable member (10, 30) that is supported by the housing, is capable of undergoing linear reciprocating motion in a range that includes: a first position, a second position, and a third position that is separated from the first position more than the second position, and is biased toward the first position; a stopper that: (i) is supported by the housing, (ii) is displaceable between a blocking position at which movement of the movable member (10, 30) from the second position to the first position is prohibited and a nonblocking position at which movement of the movable member (10, 30) from the second position to the first position is permitted, (iii) is biased toward the blocking position, and (iv) is displaced to the nonblocking position in response to a specific operation for moving the movable member (10, 30) to the first position, the specific operation being a manual opening operation; an intermittent mechanism (100, 200) that interacts with the linear reciprocating motion of the movable member (10, 30) and assumes a specific state once every two times when the movable member (10, 30) repeats the action of moving to the third position; a switch that is provided in the housing, and an electric actuator that is provided in the housing and is operably connected to the stopper; characterized in that, when the specific state is assumed, the switch is switched by the intermittent mechanism (100, 200) from one of a disconnected state and a connected state to the other of the disconnected state and the connected state; and the electric actuator displaces the stopper to the nonblocking position when energized in response to the switch being switched by the manual opening operation from one of the disconnected state and the connected state to the other of the disconnected state and the connected state. a housing; a movable member (10, 30) that is supported by the housing, is capable of undergoing linear reciprocating motion in a range that includes: a first position, a second position, and a third position that is separated from the first position more than the second position, and is biased toward the first position; a stopper that: (i) is supported by the housing, (ii) is displaceable between a blocking position at which movement of the movable member (10, 30) from the second position to the first position is prohibited and a nonblocking position at which movement of the movable member (10, 30) from the second position to the first position is permitted, (iii) is biased toward the blocking position, and (iv) is displaced to the nonblocking position in response to a specific operation for moving the movable member (10, 30) to the first position, the specific operation being a manual opening operation; an intermittent mechanism (100, 200) that interacts with the linear reciprocating motion of the movable member (10, 30) and assumes a specific state once every two times when the movable member (10, 30) repeats the action of moving to the third position; a switch that is provided in the housing, and an electric actuator that is provided in the housing and is operably connected to the stopper; when the specific state is assumed, the switch is switched by the intermittent mechanism (100, 200) from one of a disconnected state and a connected state to the other of the disconnected state and the connected state; and the electric actuator displaces the stopper to the nonblocking position when energized in response to the switch being switched by the manual opening operation from one of the disconnected state and the connected state to the other of the disconnected state and the connected state.