A medicine which contains as an active ingredient a benzothiazin-3-one-compound represented by the formula (1): (wherein n is 3 or 4; R represents ethyl or hydrogen; and R1 represents hologeno, alkoxy, haloalkyl, or haloalkoxy) or a pharmaceutically acceptable salt thereof. It is useful as a therapeutic or preventive agent for arthrosis deformans, chondrodegenerative discases such as chronic articular rheumatism, cancers, gingivitis, etc. Also provided are an intermediate for the compound and a process for producing the compound.