The invention relates an extrusion device (100) for extruding a semi¬finished product made of elastomeric material, comprising an extrusion body (10) extending along a feeding direction (A) and a pump (20) arranged downstream of the extrusion body (10) along said feeding direction (A). The extrusion body (10) comprises a hopper (30) for loading an elastomeric material and an extrusion screw (50) extending along said feeding direction (A) and having an inlet portion (50a) arranged close to the hopper (30) and an exit portion (50b) arranged close to the pump (20). The extrusion body (10) also comprises a motorised roller (40) arranged at the inlet portion (50a) of the extrusion screw (50) and configured to receive the elastomeric material from the hopper (30) and feed it to the extrusion screw (30). The extrusion screw (50) has a length and a diameter such that the ratio between length and diameter is comprised between 4 mm and 8 mm. The invention also relates to an extrusion process carried out through the aforementioned extrusion device (100).