A sliding-type compact comprising a case body for storing a cosmetic material and a retainer casing for slidably accommodating the case body therewithin, the retainer casing having at least a ceiling plate for covering an upper face of the case body slidably accommodated within the retainer casing and side plates suspended from both sides of the ceiling plate in a direction perpendicular to the sliding direction of the case body, the case body having a downwardly concaved section for containing the cosmetic material, an annular packing encircling the concaved section and extending upwards, and side walls disposed facing the side plates of the retainer casing in a state in which the case body is accommodated within the retainer casing, either the side plates or the side walls being provided with slide rails extending toward the other of the opposing side plates or side walls, the other of the side plates or side walls not provided with the slide rails being provided with guide grooves to engage with the slide rails when the case body is slid into or out from the retainer casing, both of the slide rails and the guide grooves being inclined upwards from an outermost position, where the case body is fully drawn outwardly by being slid out from the retainer casing, to an innermost position, where the case body is fully accommodated within the retainer casing, the slide rails being arranged to engage with the guide grooves such that, when the case body is fully accommodated within the retainer casing and the annular packing is pressed against the ceiling plate, the annular packing is in uniform contact with the ceiling plate (3a, wherein the slide rails are engaged with the guide grooves along the entire length thereof when the case body is fully accommodated within the retainer casing with the annular packing being pressed against the ceiling plate. the retainer casing having at least a ceiling plate for covering an upper face of the case body slidably accommodated within the retainer casing and side plates suspended from both sides of the ceiling plate in a direction perpendicular to the sliding direction of the case body, the case body having a downwardly concaved section for containing the cosmetic material, an annular packing encircling the concaved section and extending upwards, and side walls disposed facing the side plates of the retainer casing in a state in which the case body is accommodated within the retainer casing, either the side plates or the side walls being provided with slide rails extending toward the other of the opposing side plates or side walls, the other of the side plates or side walls not provided with the slide rails being provided with guide grooves to engage with the slide rails when the case body is slid into or out from the retainer casing, both of the slide rails and the guide grooves being inclined upwards from an outermost position, where the case body is fully drawn outwardly by being slid out from the retainer casing, to an innermost position, where the case body is fully accommodated within the retainer casing, the slide rails being arranged to engage with the guide grooves such that, when the case body is fully accommodated within the retainer casing and the annular packing is pressed against the ceiling plate, the annular packing is in uniform contact with the ceiling plate (3a, wherein the slide rails are engaged with the guide grooves along the entire length thereof when the case body is fully accommodated within the retainer casing with the annular packing being pressed against the ceiling plate.