A device (1) for dissolving solid chemical substances in water is provided with: a container (2), which has a bottom portion (6) designed to contain an aqueous solution; a perforated loading chamber (9), which is set at the top of the bottom portion (6) and is designed to contain a solid chemical substance (10); and a spraying device (18) set within the loading chamber (9) for directing at least one jet of water onto the solid chemical substance (10). In use, the solid chemical substance (10) is set around the spraying device (18), and the jet of water is directed downwards and/or laterally so as not to wet the solid chemical substance (10) set above the spraying device (18). In this way, there is obtained a relatively gradual dissolution of the solid chemical substance (10) and a lower development of gaseous substances having an unpleasant smell.