Interaction of shock waves discharged from the multiple slits is studied numerically and experimentally using the KAIST shock tube. Investigation is made on such distinct flow regions as flow entering the slits, flow in the narrow slits, flow in the vortex-shock interaction region, and the relatively uniform flow behind the shock front. Visualization of the shocks and vortices associated with the jets from the single, double, and multiple slits is made using the holographic interferometry and shadowgraphy, the images of which are compared with the numerical results.