A slider for fastener comprising: a first slider member formed with a projection for disengaging a male engageable member from a female engageable member both included in a fastener, the male engageable member having a projected streak portion and the female engageable member having an engagement groove into which the projected streak portion is fitted engageably and disengageably, the male and female engageable members (F1, F2) being provided, respectively, on one inner surface and the other inner surface opposed to the one inner surface in an openable end portion of a reclosable bag; and a second slider member formed with a narrowed portion for engaging the male and female engageable members (F1, F2) with each other, said slider for fastener being formed by fitting said first and second slider members (2, 3) to each other, wherein said first slider member is formed with said projection, which is adapted to be inserted forcibly between the male and female engageable members (F1, F2) included in the fastener of the reclosable bag in an engaged state from outside the fastener, and two protrusions extending toward said second slider member, and wherein said second slider member is provided with said narrowed portion, which is adapted to engage the male and female engageable members (F1, F2) with each other, and a hole into which said two protrusions are fitted, said slider for fastener having a structure in which said two protrusions on said first slider member extend out of said hole in said second slider member when said first and second slider members (2, 3) are fitted to each other, wherein the two protrusions when pinched with fingers deform elastically to come close to each other and thereby to be pulled off said hole, and the slider can be disassembled and removed from the reclosable bag into the first and second slide members (2,3). a first slider member formed with a projection for disengaging a male engageable member from a female engageable member both included in a fastener, the male engageable member having a projected streak portion and the female engageable member having an engagement groove into which the projected streak portion is fitted engageably and disengageably, the male and female engageable members (F1, F2) being provided, respectively, on one inner surface and the other inner surface opposed to the one inner surface in an openable end portion of a reclosable bag; and a second slider member formed with a narrowed portion for engaging the male and female engageable members (F1, F2) with each other, said slider for fastener being formed by fitting said first and second slider members (2, 3) to each other, wherein said first slider member is formed with said projection, which is adapted to be inserted forcibly between the male and female engageable members (F1, F2) included in the fastener of the reclosable bag in an engaged state from outside the fastener, and two protrusions extending toward said second slider member, and wherein said second slider member is provided with said narrowed portion, which is adapted to engage the male and female engageable members (F1, F2) with each other, and a hole into which said two protrusions are fitted, said slider for fastener having a structure in which said two protrusions on said first slider member extend out of said hole in said second slider member when said first and second slider members (2, 3) are fitted to each other, wherein the two protrusions when pinched with fingers deform elastically to come close to each other and thereby to be pulled off said hole, and the slider can be disassembled and removed from the reclosable bag into the first and second slide members (2,3).