A slide-type core retainer for a sample collector including a sampler tube driven into a sea floor. The slide-type core retainer includes a catcher holder detachably coupled to a tip end of the sampler tube; a catcher installed on an inner peripheral surface of a tip end of the catcher holder and configured to allow sediment introduction into the sampler tube and preventing sediment from being lost using resiliency. A control member slidably installed inside the catcher holder controls opening and closing of the catcher. The control member is coupled to the catcher before sample collection so that the catcher remains opened. The control member slides into an inner side of the catcher holder while being separated from the catcher by the resistance of the solid sediment such that the catcher is closed, when resistance is generated by solid sediment after the sampler tube is driven into the sediment.