A work device includes a work device body and a contact preventer. The work device body includes a linear motion unit having three degrees of freedom and a rotary unit having three degrees of freedom. An end effector is mounted on an output portion of the rotary unit. The contact preventer separates a working region in which the work device body is installed, from a non-working region outside the working region. The contact preventer includes: an entry allowing portion allowing an object to enter the working region therethrough; and an entry allowing portion entry detection sensor configured to detect entry of an object into the working region through the entry allowing portions.