A holder for securing a fluid tube to a trough-formed solar collector. In an operation mode of the solar collector, the holder partly encircles a circumference of a cross-section of the fluid tube and leaves a portion of the circumference un-encircled by the holder. The holder may comprise a base member adapted to abut the fluid tube, the base member comprising at least one securing means adapted to secure the base member to the solar collector. Further, the holder may comprise an immobilizing member adapted to together with the base member immobilize a centre-line of the fluid tube in the solar collector when the fluid tube abuts the holder. The base member is connected with the immobilizing member, such that the base member together with the immobilizing member, in an operation mode of the solar collector, partly encircles the circumference of the cross-section of the fluid tube and forms an opening smaller than a diameter of the cross-section of the fluid tube. The immobilizing member may be pivotably connected to the base member by a connecting means, such that the immobilizing member can pivot in relation to the base member to, in a service mode of the solar collector, leave an opening larger than the diameter of the cross-section of the fluid tube.