Method of making a sink from flat, low-porosity, compact porcelain ceramic material slabs, characterized in that it comprises the following steps - a first step consisting cutting out the material that will constitute the bottom of the sink; - a second step consisting of making the hole for the drain in the bottom of the sink; - a third step consisting of supporting the edges of the bottom of the sink on a flat support and applying a mechanical force on the rim of the hole for the drain in the bottom of the sink; - a fourth step consisting of subjecting this flat slab forming the bottom of the sink to a gradual and stepwise heating until reaching a heating temperature greater than the annealing temperature and less than the melting temperature of the compact ceramic material, without the physical or chemical properties of said material changing, such that the mechanical force applied on the rim of the hole for the drain in the bottom of the sink deforms said surface, a continuous surface inclined towards the drain being obtained; - a fifth step of cooling the flat slab constituting the bottom of the sink with the new shape it has taken on, consisting of cooling performed in a gradual and stepwise manner until reaching room temperature, preventing residual stresses of the material used; - a sixth step consisting of placing additional flat slabs around the slab constituting the bottom of the sink, on the sides thereof, to constitute the sides of the sink, being bonded together by bonding means; - a seventh step consisting of externally coating the assembly made with a reinforcement consisting of resins, glass fiber, mineral fillers, etc., increasing the strength of the sink made; - finally, a last step consisting of bonding the upper part of the additional slabs, constituting the side body of the sink, to the edges of the opening in the countertop where the sink is located. - a first step consisting cutting out the material that will constitute the bottom of the sink; - a second step consisting of making the hole for the drain in the bottom of the sink; - a third step consisting of supporting the edges of the bottom of the sink on a flat support and applying a mechanical force on the rim of the hole for the drain in the bottom of the sink; - a fourth step consisting of subjecting this flat slab forming the bottom of the sink to a gradual and stepwise heating until reaching a heating temperature greater than the annealing temperature and less than the melting temperature of the compact ceramic material, without the physical or chemical properties of said material changing, such that the mechanical force applied on the rim of the hole for the drain in the bottom of the sink deforms said surface, a continuous surface inclined towards the drain being obtained; - a fifth step of cooling the flat slab constituting the bottom of the sink with the new shape it has taken on, consisting of cooling performed in a gradual and stepwise manner until reaching room temperature, preventing residual stresses of the material used; - a sixth step consisting of placing additional flat slabs around the slab constituting the bottom of the sink, on the sides thereof, to constitute the sides of the sink, being bonded together by bonding means; - a seventh step consisting of externally coating the assembly made with a reinforcement consisting of resins, glass fiber, mineral fillers, etc., increasing the strength of the sink made; - finally, a last step consisting of bonding the upper part of the additional slabs, constituting the side body of the sink, to the edges of the opening in the countertop where the sink is located.