An intermeshing type twin screw extruder comprising: - a pair of screws provided with round sectional portions having a diameter that is smaller than an outer diameter of a mixing wing portion on the downstream side of the mixing wing portion for mixing an object to be mixed, - a barrel within which the pair of screws are aligned, and - a mixing degree adjusting device for adjusting a mixing degree of an object to be mixed by regulating a flow rate of the object to be mixed that flows along the round sectional portions, the mixing degree adjusting device being provided at a position corresponding to said round sectional portions in the intermeshing type twin screw extruder, the mixing degree adjusting device comprising: - a pair of spacer members (22a, 22b) arranged at a position sandwiching both said round sectional portions from both sides in the aligning direction of said pair of screws; and - a pair of drawing members (23a, 23b) arranged at a position sandwiching both said round sectional portions from both sides in the orthogonal direction that is orthogonal to the aligning direction, said spacer members (22a, 22b) being movable between: - an adjusting position for coming into the inside of the outer diameter of said mixing wing portion in the aligning direction and opposing to the round sectional portions, and - a retracting position, and said spacer members (22a, 22b) comprising opposing portions (41a, 41b) opposing to said round sectional portions at the time of moving to the adjusting position, and said drawing members (23a, 23b) being formed in a shape in which end parts thereof on the both round sectional portions side are along peripheral surfaces of said round sectional portions, movable in the direction approaching to and retracting from said round sectional portions along said opposing portions (41a, 41b) in an area intervening between said opposing portions (41a, 41b) of both said spacer members (22a, 22b) at the time of moving to the adjusting position, characterized in that the extruder is adapted such that when said screws are to be extracted from said barrel, the spacer members (22a, 22b) are retractable to the outside until the passage of said screws is accepted, wherein said opposing portions (41a, 41b) opposing to said round sectional portions at the time of moving to the adjusting position being formed in a substantially linear shape extending substantially in parallel with the orthogonal direction seen from the axial direction of said screws. - a pair of screws provided with round sectional portions having a diameter that is smaller than an outer diameter of a mixing wing portion on the downstream side of the mixing wing portion for mixing an object to be mixed, - a barrel within which the pair of screws are aligned, and - a mixing degree adjusting device for adjusting a mixing degree of an object to be mixed by regulating a flow rate of the object to be mixed that flows along the round sectional portions, the mixing degree adjusting device being provided at a position corresponding to said round sectional portions in the intermeshing type twin screw extruder, the mixing degree adjusting device comprising: - a pair of spacer members (22a, 22b) arranged at a position sandwiching both said round sectional portions from both sides in the aligning direction of said pair of screws; and - a pair of drawing members (23a, 23b) arranged at a position sandwiching both said round sectional portions from both sides in the orthogonal direction that is orthogonal to the aligning direction, - an adjusting position for coming into the inside of the outer diameter of said mixing wing portion in the aligning direction and opposing to the round sectional portions, and - a retracting position, and