A strainer device for a drum, the strainer device comprising: a fixing portion attachable to a shell of the drum; an operation portion configured to be rotatable with respect to the fixing portion; a movable portion configured to be moved with respect to the fixing portion in accordance with a rotation of the operation portion to change a snare wire between an ON state where the snare wire is in contact with a drum head of the drum and an OFF state where the snare wire is separated from the drum head; a pressing member; a cam portion including a cam surface provided on one of the movable portion or the operation portion; and characterized by a follower provided on the other of the movable portion or the operation portion, and configured to be relatively displaced with respect to the cam portion between a first position and a second position in the cam portion in accordance with the rotation of the operation portion while the pressing member is pressing the follower against the cam surface of the cam portion, wherein a direction of a force acting on the follower with respect to the cam portion is directed to: a side of the first position within the cam portion in a state where the follower is disposed in the first position; and a side of the second position in a state where the follower is disposed in the second position, wherein the direction of the force acting on the follower with respect to the cam portion is switched between the side of the first position and the side of the second position, wherein the ON state of the snare wire is where the follower is disposed in the first position and the OFF state of the snare wire is where the follower is disposed in the second position, wherein the cam follower is movable to an intermediate position between the first position and the second position, the intermediate position being closer to the first position than the second position, wherein the cam surface at which the cam follower is disposed in the intermediate position includes a convex portion, and wherein a positive resistance of the follower is generated as the follower moves over the convex portion. a fixing portion attachable to a shell of the drum; an operation portion configured to be rotatable with respect to the fixing portion; a movable portion configured to be moved with respect to the fixing portion in accordance with a rotation of the operation portion to change a snare wire between an ON state where the snare wire is in contact with a drum head of the drum and an OFF state where the snare wire is separated from the drum head; a pressing member; a cam portion including a cam surface provided on one of the movable portion or the operation portion; and characterized by a follower provided on the other of the movable portion or the operation portion, and configured to be relatively displaced with respect to the cam portion between a first position and a second position in the cam portion in accordance with the rotation of the operation portion while the pressing member is pressing the follower against the cam surface of the cam portion, wherein a direction of a force acting on the follower with respect to the cam portion is directed to: a side of the first position within the cam portion in a state where the follower is disposed in the first position; and a side of the second position in a state where the follower is disposed in the second position, a side of the first position within the cam portion in a state where the follower is disposed in the first position; and a side of the second position in a state where the follower is disposed in the second position, wherein the direction of the force acting on the follower with respect to the cam portion is switched between the side of the first position and the side of the second position, wherein the ON state of the snare wire is where the follower is disposed in the first position and the OFF state of the snare wire is where the follower is disposed in the second position, wherein the cam follower is movable to an intermediate position between the first position and the second position, the intermediate position being closer to the first position than the second position, wherein the cam surface at which the cam follower is disposed in the intermediate position includes a convex portion, and wherein a positive resistance of the follower is generated as the follower moves over the convex portion.