PURPOSE: To simply load or unload a work onto or from a honing device for grinding the through hole of the work to the prescribed inner diameter.

CONSTITUTION: This honing device is provided with the first driving means 10 nearly symmetrically moving a grinding shaft rod 90 and an expanding shaft rod 91 near to or apart from each other and switching the tip sections 90a, 91a of both shaft rods 90, 91 to the retreat position released from the machined hole of a work W and the action position entered into the machined hole of the work W, the second driving means 15 integrally reciprocating both shaft rods 90, 91 and integrally reciprocating the tip sections 90a, 91a of both shaft rods 90, 91 in the machined hole of the work W, the third driving means 27 relatively moving both shaft rods 90, 91 located at the action position nearer to each other and gradually increasing the rotating radius of the grinding action section of one shaft rod 90 via the sliding action between the expanding acted face and the expanding acting face of both shaft rod tip sections 90a, 91a, and the fourth driving means 60 rotatively driving both shaft rods 90, 91 in the same direction at the same speed.