The invention provides a separable bottom end stop for a concealed slide fastener, in which reinforcement portions (20, 21) for reinforcing bent edge portions (24) of a fastener tape (T) are respectively molded integrally with a box pin (2) and a separable pin (3) using resin, such that the reinforcement portions (20, 21) are swollen from a top surface of the fastener tape (T), while the reinforcement portion (20) on the side of the box pin (2) is formed such that a bottom end thereof is in the same plane as the box pin (2). A front end of the reinforcement portion (21) on the side of the separable pin (3) has a protruded portion (32) which is protruded in parallel to the separable pin (3) and a box (1) has an L-shaped engaging portion (17) and a contact portion (16), provided on a surface thereof. When the box pin (2) is inserted into and fixed to the box (1) while the separable pin (3) is inserted into an insertion hole (6), the protruded portion (32) of the reinforcement portion (21) makes contact with the engaging portion (17). Consequently, when the separable pin (3) is inserted into the box (1), the separable pin (3) never rolls inside the box (1) due to pulling force.