A plate-like storage box with a box body (1), includes a soleplate (6) and a cover plate (7) extending in parallel with the soleplate, and a plurality of storage cavities (8) provided on a plane in parallel with the soleplate and the cover plate (6, 7), adjacent to each other and separated from each other, wherein a first cavity (8) is designed for storing functional members (9) such as knives, forfexes, pens, and a second storage cavity (8) is provided with an illumination device (221), the illumination device (221) comprises a light source (239) having a first and second electric conductive sheets (240), a battery (234) and an operation member (289), characterized in that, the operation member (289) is movably guided along a guide device (200), and comprises a support seat (308), the battery (234) can be inserted into the support seat, the second electric conductive sheet and the first electric conductive sheet are distributed tiltingly, and the battery (234) is conductively connected to the first electric conductive sheet (240) by a first electrode face, and is moved relatively to the second storage cavity (8) by the operation member (289), when a second electrode face (235) of the battery (234) reaches the second electric conductive sheet (240), a contact closes and a light source (239) begins to emit.