In a case having a cover and a case body connected to each other via a shaft and a shaft inserting portion, a quantity of gel to be used can be reduced while a braking effect of the cover is satisfactorily secured. A shaft is inserted into a shaft inserting portion such that a cover is turned with respect to a case body on the shaft to be opened. An urging mechanism urges the cover in an opening direction. A viscous material is disposed between the shaft and the shaft inserting portion such that the cover is slowly opened with respect to the case body. An engaging projection is disposed at the shaft inserting portion while an engaged recess engageable with the engaging projection is disposed the shaft to enlarge a contact area between the shaft and the shaft inserting portion via the viscous material.