The present invention relates to an arrangement (1) for easy installing and stably supporting a ladder (2) in a passageway or manhole (7), such that damage to the wall (4) of the passageway due to for example penetration of fastening means is minimized. The invention provides an arrangement for supporting a ladder (2) comprising positioning brackets (5, 105) for positioning the lower part of the ladder at a distance from the inside wall (4), which positioning brackets are secured against the surface of the inner wall by a resilient elongated member (6). By bending this elongated member (6) in a ring shape and positioning this member inside the passageway (7), it exerts a radially directed force and thus clamps itself in position against the wall (4). Because the elongated member (6) clamps itself in a fixed position, the elongated member dos not need to be secured to the wall (4) by for example bolts. Thus the wall (4) maintains its structural integrity.