To provide an inner surface polishing machine for a glass tube capable of polishing the inner surface of the glass tube without a variation and with high productivity.

This inner surface polishing machine for the glass tube includes: a glass tube rotating mechanism 2 for holding and rotating the glass tube; a wire 3 stretched through the glass tube to travel at least in one direction; a driving mechanism 4 for traveling the wire 3; a polishing head 5 fitted to the wire 3, traveling in the glass tube and provided with a polishing head unit 5a; and a hydraulic mechanism 6 for pressing the polishing head unit 5a to the glass tube.