A collapsible ladder comprising: several collapsible ladder sections, each or at least part of the ladder sections comprising two hollow ladder bars (101a,b,c, 102a,b,c, 203) arranged parallel to each other and interconnected at an upper end by a rung (103a,b,c, 201), and each collapsible ladder section being telescopically inserted into a lower ladder section; wherein each ladder bar (101a,b,c, 102a,b,c, 203) of a collapsible ladder section has a locking hole adjacent the lower end part of the ladder bar (101a,b,c, 102a,b,c, 203) and an extension below the locking hole; wherein retaining mechanisms are provided in at least part of the rungs for locking the collapsible ladder sections relative to one another when the collapsible ladder sections are extended, each of or part of said retaining mechanisms comprising a locking pin, which can be brought into an extended and locked position in order to engage a corresponding locking hole provided in the ladder bar of a ladder section positioned there above, and a release part for bringing the locking pin into a retracted and un-locked position; wherein at least part of the rungs (201, 220, 226, 231) holding a retaining mechanism with a locking pin and a release part further have spacers (204, 222, 228, 233) provided at the bottom with at least part of said spacers (204, 222, 228, 233) having a release actuator (205, 223, 230, 234) with a bottom part, said release actuator (205, 223, 230, 234) engaging the release part of a retaining mechanism of the rung and being arranged to activate the release part when the bottom part of the release actuator (205, 223, 230, 234) is moved upwards through the spacer (204, 222, 228, 233) thereby bringing the locking pin into the un-locked position; characterised in that at least part of the rungs (220, 226, 231) have one or more projecting parts (221, 227, 232) at the upper surface, said projecting part(s) (221, 227, 232) being arranged below the release actuator(s) (223, 230, 234) arranged in the central part of the spacers(s) (222, 228, 233) provided at the bottom of a rung positioned there above, whereby when the above positioned rung is moved downwards until the spacer(s) (222, 228, 233) rest at the rung surface of the below positioned rung (220, 226, 231), the release actuator (223, 230, 234) of a spacer (222, 228, 233) provided at the bottom of the above positioned rung is contacting a projecting part (221, 227, 232) at the upper surface of the below positioned rung (220, 226, 231) and moved upwards through the spacer (222, 228, 233) thereby bringing the locking pin into the un-locked position. several collapsible ladder sections, each or at least part of the ladder sections comprising two hollow ladder bars (101a,b,c, 102a,b,c, 203) arranged parallel to each other and interconnected at an upper end by a rung (103a,b,c, 201), and each collapsible ladder section being telescopically inserted into a lower ladder section; wherein each ladder bar (101a,b,c, 102a,b,c, 203) of a collapsible ladder section has a locking hole adjacent the lower end part of the ladder bar (101a,b,c, 102a,b,c, 203) and an extension below the locking hole; wherein retaining mechanisms are provided in at least part of the rungs for locking the collapsible ladder sections relative to one another when the collapsible ladder sections are extended, each of or part of said retaining mechanisms comprising a locking pin, which can be brought into an extended and locked position in order to engage a corresponding locking hole provided in the ladder bar of a ladder section positioned there above, and a release part for bringing the locking pin into a retracted and un-locked position; wherein at least part of the rungs (201, 220, 226, 231) holding a retaining mechanism with a locking pin and a release part further have spacers (204, 222, 228, 233) provided at the bottom with at least part of said spacers (204, 222, 228, 233) having a release actuator (205, 223, 230, 234) with a bottom part, said release actuator (205, 223, 230, 234) engaging the release part of a retaining mechanism of the rung and being arranged to activate the release part when the bottom part of the release actuator (205, 223, 230, 234) is moved upwards through the spacer (204, 222, 228, 233) thereby bringing the locking pin into the un-locked position; characterised in that at least part of the rungs (220, 226, 231) have one or more projecting parts (221, 227, 232) at the upper surface, said projecting part(s) (221, 227, 232) being arranged below the release actuator(s) (223, 230, 234) arranged in the central part of the spacers(s) (222, 228, 233) provided at the bottom of a rung positioned there above, whereby when the above positioned rung is moved downwards until the spacer(s) (222, 228, 233) rest at the rung surface of the below positioned rung (220, 226, 231), the release actuator (223, 230, 234) of a spacer (222, 228, 233) provided at the bottom of the above positioned rung is contacting a projecting part (221, 227, 232) at the upper surface of the below positioned rung (220, 226, 231) and moved upwards through the spacer (222, 228, 233) thereby bringing the locking pin into the un-locked position.