To provide a gear pump capable of freely controlling rubber ullage.

The gear pump for rubber extrusion is constituted by forming a plural number of recessed channels for rubber flow. The channels extend from each of shaft equivalent positions of each of gears to each of bottom equivalent positions of each of tooth spaces of each of the gears on at least one surface of respective both side surfaces of a pair of the gears and housing inner surfaces directly facing each of these both side surfaces.