A cutter with a slider that can be pushed from two directions has a housing, a blade holder, a slider, and a blade. The slider is mounted moveably on the housing, is connected to the blade holder, and has an upper sliding element, a lower sliding element, and a resilient tab engaging at least one tooth formed on the blade holder. The upper sliding element has an L-shaped cross section to form a top wall and a side wall corresponding respectively to a top wall and a side wall of the housing. A guiding recess is defined by the side wall of the upper sliding element to slidably receive a portion of the side wall of the housing that forms an edge of a guiding channel. Accordingly, the cutter is convenient in use.
