A disclosed method for producing an elongated filler-containing fluororesin sheet includes: a step (I) of forming a strip member from a strip sheet containing a fluororesin, a filler, and a forming aid; and a step (II) of forming an elongated sheet strip by rolling the strip member in a longitudinal direction of the strip member. In the step (I), the strip member is formed by bending the strip sheet in such a manner that quadrilaterals formed on a surface of the strip member, each defined by two strip member side edges extending in the longitudinal direction of the strip member and two strip sheet side edges of the strip sheet that crosses a region between the two strip member side edges are parallelograms each having an acute angle α as an interior angle and that the parallelograms are arranged in the longitudinal direction of the strip member.