An endoscope system comprising: a first elongate member inserted into a subject; a conduit which, being provided on the first elongate member, communicates a proximal opening and a distal opening of the first elongate member; a second elongate member which is inserted through the proximal opening, passed through the conduit in such a way that a distal end of the second elongate member can stick out of the distal opening, and movable relative to the first elongate member in a direction of the passage; a first shape-holding section provided on the first elongate member and capable of switching at least part of the first elongate member between a flexible and deformable first state and a shape-held second state; a second shape-holding section provided on at least part of the second elongate member in such a way as to include at least part of a portion which can stick out of the distal opening and capable of switching the at least part of the second elongate member between a flexible and deformable first state and a shape-held second state; and first fixing means which is provided on a distal end side with respect to the first shape-holding section of the first elongate member, and is configured to fix the first elongate member to the subject by abutting the subject; second fixing means which is provided on a distal end side with respect to the second shape-holding section of the second elongate member and is configured to fix the second elongate member to the subject by abutting the subject, and a control means (31, 33) adapted to switch the first and second shape-holding sections between their respective first state and the second state and fixes and unfixes the first and second elongate members member to the subject by the respective first and second fixing means, wherein the control means is adapted to switch the first and second shape-holding sections from the second state to the first state with their respective first and second elongate members fixed to the subject by their respective first and second fixing means, wherein only one of the first elongate member and the second elongate member advances in an insertion direction at a time, the first fixing means or second fixing means provided at one of the first and second elongate members (2, 1) which does not advance always fixes the one of the first and second elongate members (2, 1) to the subject not to advance to an insertion side, and the one of the first and second elongate members (2, 1) which does not advance is subjected to the shape-holding. a first elongate member inserted into a subject; a conduit which, being provided on the first elongate member, communicates a proximal opening and a distal opening of the first elongate member; a second elongate member which is inserted through the proximal opening, passed through the conduit in such a way that a distal end of the second elongate member can stick out of the distal opening, and movable relative to the first elongate member in a direction of the passage; a first shape-holding section provided on the first elongate member and capable of switching at least part of the first elongate member between a flexible and deformable first state and a shape-held second state; a second shape-holding section provided on at least part of the second elongate member in such a way as to include at least part of a portion which can stick out of the distal opening and capable of switching the at least part of the second elongate member between a flexible and deformable first state and a shape-held second state; and first fixing means which is provided on a distal end side with respect to the first shape-holding section of the first elongate member, and is configured to fix the first elongate member to the subject by abutting the subject; second fixing means which is provided on a distal end side with respect to the second shape-holding section of the second elongate member and is configured to fix the second elongate member to the subject by abutting the subject, and a control means (31, 33) adapted to switch the first and second shape-holding sections between their respective first state and the second state and fixes and unfixes the first and second elongate members member to the subject by the respective first and second fixing means, wherein the control means is adapted to switch the first and second shape-holding sections from the second state to the first state with their respective first and second elongate members fixed to the subject by their respective first and second fixing means, wherein only one of the first elongate member and the second elongate member advances in an insertion direction at a time, the first fixing means or second fixing means provided at one of the first and second elongate members (2, 1) which does not advance always fixes the one of the first and second elongate members (2, 1) to the subject not to advance to an insertion side, and the one of the first and second elongate members (2, 1) which does not advance is subjected to the shape-holding.