A conduit control device includes a cylinder member 30, a piston member 60 including a shaft section 61 and a button section 64, an attachment section 40 including a rigid cylinder 42 and an elastic cylinder 41, a compression spring 80 suspended between the button section 64 and the rigid cylinder 42, a first elastic member 90 provided on an upward direction P1 side with respect to a position at which one end of the compression spring 80 comes into contact in the button section 64, the first elastic member 90 being brought into contact with a contact surface 42d of the rigid cylinder 42 and elastically deformed to thereby seal a gap S1 in a state in which the piston member 60 is depressed via the button section 64, and a second elastic member 41q brought into contact with an exterior member 103g and elastically deformed to thereby seal a gap S2 in a state in which the piston member 60 is depressed via the button section 64.