A high-quality parison is supplied by maintaining an appropriate tension state while restricting a parison discharged from an extrusion die constantly. A parison supply device (1) that continuously supplies, to a blow molding die, parison sections (Ps) of a parison (P) discharged from an extrusion die (10), the parison section having a specified length. The parison supply device includes a plurality of tension chucks (2) and a tension chuck operation unit (3) that operates the plurality of tension chucks (2). The tension chuck operation unit (3) causes the individual tension chucks (2A and 2B) to perform a repeated operation of grasping the parison (P) at a first position (I) near the extrusion die (10) and moving to a second position (II) separated from the extrusion die (10) such that, before the preceding tension chuck (2A) is separated by a set distance (L) from the extrusion die (10) at the second position (II), the following tension chuck (2B) grasps the parison (P) at the first position (I), and then the parison section is supplied to the blow molding die.