A method of producing a retardation film, comprising: holding left and right end portions of a film with left and right variable pitch-type clips configured to have clip pitches changing in a longitudinal direction, respectively (in the following referred to as holding step); preheating the film (in the following referred to as preheating step); performing at least one selected from the following (i) and (ii), while extending a distance between the left and right clips, to obliquely stretch the film (in the following referred to as oblique stretching step): (i) making a change ratio of the clip pitch of the clips on one side in a traveling direction thereof and a change ratio of the clip pitch of the clips on another side in a traveling direction thereof different from each other, and (ii) making a position at which the clip pitch of the clips on the one side in the traveling direction starts to change and a position at which the clip pitch of the clips on the another side in the traveling direction starts to change different from each other; and releasing the clips holding the film (in the following referred to as releasing step), wherein the left and right clips are configured to be variable pitch type by utilizing a link mechanism; and the method being characterised in that moving speeds of the clips are braked by engaging a high-torque sprocket and/or a constant-speed rotating sprocket with the link mechanism and thereby applying a load to the link mechanism, immediately before the holding step and/or during a time period from the holding step to the oblique stretching step. holding left and right end portions of a film with left and right variable pitch-type clips configured to have clip pitches changing in a longitudinal direction, respectively (in the following referred to as holding step); preheating the film (in the following referred to as preheating step); performing at least one selected from the following (i) and (ii), while extending a distance between the left and right clips, to obliquely stretch the film (in the following referred to as oblique stretching step): (i) making a change ratio of the clip pitch of the clips on one side in a traveling direction thereof and a change ratio of the clip pitch of the clips on another side in a traveling direction thereof different from each other, and (ii) making a position at which the clip pitch of the clips on the one side in the traveling direction starts to change and a position at which the clip pitch of the clips on the another side in the traveling direction starts to change different from each other; and (i) making a change ratio of the clip pitch of the clips on one side in a traveling direction thereof and a change ratio of the clip pitch of the clips on another side in a traveling direction thereof different from each other, and (ii) making a position at which the clip pitch of the clips on the one side in the traveling direction starts to change and a position at which the clip pitch of the clips on the another side in the traveling direction starts to change different from each other; and releasing the clips holding the film (in the following referred to as releasing step), wherein the left and right clips are configured to be variable pitch type by utilizing a link mechanism; and the method being characterised in that moving speeds of the clips are braked by engaging a high-torque sprocket and/or a constant-speed rotating sprocket with the link mechanism and thereby applying a load to the link mechanism, immediately before the holding step and/or during a time period from the holding step to the oblique stretching step.