A slide fastener with a separable bottom end stop, comprising: a box pin continuously arranged at a lower end of a first element row which is disposed at one side edge of a first fastener stringer; an insert pin continuously arranged at a lower end of a second element row which is disposed at one side edge of a second fastener stringer configured to be capable of being separated from the first fastener stringer; and a top slider for upper opening including an automatic stopper which is constituted with a pawl member having a stop pawl formed to be capable of protruding from and retreating to a pawl hole opened in a front blade with respect to an element guide passage formed between the front blade to cover a front side and a back blade to cover a back side of the first element row and the second element row, an urging member to resiliently urge the stop pawl in a direction of protruding into the element guide passage, and a tab capable of raising the stop pawl in a direction of being withdrawn from the element guide passage by disposing a tab pivot portion between the front blade and the pawl member and upwardly moving the tab pivot portion, being characterized in that the stop pawl protruding into the element guide passage is configured to be movable in a lateral direction toward the insert pin side and the box pin side, the pawl hole has an opening to enable a movement of the stop pawl, and the insert pin comprises a retreat contact portion to gradually retreat the stop pawl to the box pin side as being contacted with the stop pawl which protrudes into the element guide passage when the insert pin is inserted into the top slider from a separated state. a box pin continuously arranged at a lower end of a first element row which is disposed at one side edge of a first fastener stringer; an insert pin continuously arranged at a lower end of a second element row which is disposed at one side edge of a second fastener stringer configured to be capable of being separated from the first fastener stringer; and a top slider for upper opening including an automatic stopper which is constituted with a pawl member having a stop pawl formed to be capable of protruding from and retreating to a pawl hole opened in a front blade with respect to an element guide passage formed between the front blade to cover a front side and a back blade to cover a back side of the first element row and the second element row, an urging member to resiliently urge the stop pawl in a direction of protruding into the element guide passage, and a tab capable of raising the stop pawl in a direction of being withdrawn from the element guide passage by disposing a tab pivot portion between the front blade and the pawl member and upwardly moving the tab pivot portion, being characterized in that the stop pawl protruding into the element guide passage is configured to be movable in a lateral direction toward the insert pin side and the box pin side, the pawl hole has an opening to enable a movement of the stop pawl, and the insert pin comprises a retreat contact portion to gradually retreat the stop pawl to the box pin side as being contacted with the stop pawl which protrudes into the element guide passage when the insert pin is inserted into the top slider from a separated state.