To improve the processing efficiency of semi-dry processing.

This semi-dry processing device is a semi-dry processing tool 1 provided with a cutting edge 2, a tip portion 8 having the groove 3 of helical edge for exhausting hips and continuous shank portion 9 at the tip portion 8, and is characterized to be provided with the semi-dry processing tool 1 or a cutting edge 22 characterized to be provided with a mist passage 4 for ejecting mists to the groove 3 of the helical edge with continuously passing through the groove 3 of the helical edge, a tip potion 28 having the groove 23 of a helical edge for exhausting chips, a semi-dry processing tool 21 provided with a continuous shank portion 29 at the tip portion 28, and a mist passage 29 for ejecting the mists to the groove 23 of the helical edge on the holding portion 25 by providing the holding portion 25 for holding the shank 29 on the shank portion 9.