A pharmaceutical injection device, comprising: a main body case (1, 1001) having a pharmaceutical syringe attachment component (7, 1007) on its distal end side; a distal end cap (2, 1002) removably attached to the distal end side of the main body case (1, 1001); a first driver (8, 1008) that moves a pharmaceutical syringe unit (10, 1010) attached to the pharmaceutical syringe attachment component (7, 1007) to the distal end side or the rear side along with the pharmaceutical syringe attachment component (7, 1007); a second driver (9, 1009) that moves a gasket (34, 1041) of a pharmaceutical syringe (15, 1040) constituting the pharmaceutical syringe unit (10, 1010) to the distal end side; and a controller (22, 1016) that is connected to the first driver (8, 1008) and the second driver (9, 1009), wherein the controller (22, 1016) uses the first driver (8, 1008) to move the pharmaceutical syringe unit (10, 1010) to a needle operation position in which an injection needle (20, 1014) is attached to the pharmaceutical syringe unit (10, 1010) or is removed from the pharmaceutical syringe unit (10, 1010), said operation position being closer to the distal end side than a needle removal position, the needle operation position is closer to the distal end side than a needle insertion position, the needle operation position is a position at which at least part of a large-diameter part provided on a rear side of a needle case covering the injection needle (20, 1014) is exposed from a distal end opening in the distal end cap (2, 1002) for the user's fingers to turn the needle case for attachment, in a state in which the needle case has been attached to the pharmaceutical syringe unit (10, 1010), the needle removal position is a position at which the injection needle (20, 1014) is disposed inside the distal end cap (2, 1002) and does not protrude from the distal end cap (2, 1002), and the needle insertion position is a position at which a pharmaceutical is injected into a subject and at which a portion of the injection needle (20, 1014) is located on the distal end side of the distal end cap (2, 1002). a main body case (1, 1001) having a pharmaceutical syringe attachment component (7, 1007) on its distal end side; a distal end cap (2, 1002) removably attached to the distal end side of the main body case (1, 1001); a first driver (8, 1008) that moves a pharmaceutical syringe unit (10, 1010) attached to the pharmaceutical syringe attachment component (7, 1007) to the distal end side or the rear side along with the pharmaceutical syringe attachment component (7, 1007); a second driver (9, 1009) that moves a gasket (34, 1041) of a pharmaceutical syringe (15, 1040) constituting the pharmaceutical syringe unit (10, 1010) to the distal end side; and a controller (22, 1016) that is connected to the first driver (8, 1008) and the second driver (9, 1009), wherein the controller (22, 1016) uses the first driver (8, 1008) to move the pharmaceutical syringe unit (10, 1010) to a needle operation position in which an injection needle (20, 1014) is attached to the pharmaceutical syringe unit (10, 1010) or is removed from the pharmaceutical syringe unit (10, 1010), said operation position being closer to the distal end side than a needle removal position, the needle operation position is closer to the distal end side than a needle insertion position, the needle operation position is a position at which at least part of a large-diameter part provided on a rear side of a needle case covering the injection needle (20, 1014) is exposed from a distal end opening in the distal end cap (2, 1002) for the user's fingers to turn the needle case for attachment, in a state in which the needle case has been attached to the pharmaceutical syringe unit (10, 1010), the needle removal position is a position at which the injection needle (20, 1014) is disposed inside the distal end cap (2, 1002) and does not protrude from the distal end cap (2, 1002), and the needle insertion position is a position at which a pharmaceutical is injected into a subject and at which a portion of the injection needle (20, 1014) is located on the distal end side of the distal end cap (2, 1002).