A cascade-type thrust reverser, comprising: - a fixed front frame, - a plurality of cascade vanes secured to this front frame, - a sliding cowl mounted between a direct jet position where it covers these cascades, and a reverse jet position in which it uncovers these cascades, - at least one housing for receiving a thrust reverser flap formed in the upstream portion of the sliding cowl, - at least one thrust reverser flap pivotally mounted in this housing, between a direct jet position where it is stored in this housing, and a reverse jet position in which it is out of this housing, and - a connecting rod mechanism (11, 13) connecting said front frame to said flap, adapted to pivot this flap from its direct jet position to its reverse jet position under the effect of the sliding of said cowl from its direct jet position to its reverse jet position, this thrust reverser being remarkable in that it comprises a first hook fixedly mounted within said housing, and in that said connecting rod mechanism (11, 13) comprises a telescopic connecting rod comprising: - a body provided with a second hook, - a rod slidably mounted within this body, - a spring returning this rod in the extended position relative to the body, and - a stop (21, 31) preventing the rod to get out from the body, - the assembly of these members being arranged so that: - when said sliding cowl and said flap are in the direct jet position, said second hook is held in engagement with said first hook and said flap is immobilized at the bottom of said housing by said rod subjected to a pre-stress generated by said compressed spring, and - when said sliding cowl is at the beginning of sliding from its direct jet position to its reverse jet position, said second hook is disengaged from said first hook and said rod comes in extended abutment in said body, allowing to rotate said flap from its direct jet position to its reverse jet position under the tensile force exerted by said rod. - a fixed front frame, - a plurality of cascade vanes secured to this front frame, - a sliding cowl mounted between a direct jet position where it covers these cascades, and a reverse jet position in which it uncovers these cascades, - at least one housing for receiving a thrust reverser flap formed in the upstream portion of the sliding cowl, - at least one thrust reverser flap pivotally mounted in this housing, between a direct jet position where it is stored in this housing, and a reverse jet position in which it is out of this housing, and - a connecting rod mechanism (11, 13) connecting said front frame to said flap, adapted to pivot this flap from its direct jet position to its reverse jet position under the effect of the sliding of said cowl from its direct jet position to its reverse jet position, - a body provided with a second hook, - a rod slidably mounted within this body, - a spring returning this rod in the extended position relative to the body, and - a stop (21, 31) preventing the rod to get out from the body, - the assembly of these members being arranged so that: - when said sliding cowl and said flap are in the direct jet position, said second hook is held in engagement with said first hook and said flap is immobilized at the bottom of said housing by said rod subjected to a pre-stress generated by said compressed spring, and - when said sliding cowl is at the beginning of sliding from its direct jet position to its reverse jet position, said second hook is disengaged from said first hook and said rod comes in extended abutment in said body, allowing to rotate said flap from its direct jet position to its reverse jet position under the tensile force exerted by said rod.