To provide a dancer roller device in which tension of a linear member can be securely controlled in spite of simple constitution.

In a dancer roller device provided with a fixed roller 2, and a dancer roller 3 disposed under that for adjusting a linear speed of a linear member 10 as the linear member is wound around the fixed roller 2 and the dancer roller 3, the dancer roller 3 is moved in such a direction as to generate a deflection angle to a vertical line suspended from the fixed roller 2, and this deflection angle is changed to control tension applied to the linear member 10 by a tension changeable control means.