Infrared radiation fire detector, comprising a curved support surface and a plurality of infrared radiation sensors arranged on the support surface. Each sensor comprises a planar array of infrared radiation-sensitive elements, having a respective sight direction and a solid angle of view defined around the sight direction, which define a field of view associated to the sensor. The sight directions of the sensors intersect with one another at a central point and the sensors are spaced apart from one another by a given angular distance referred to the central point, the solid angles of view of the sensors having a same narrow width so that the fields of view of the sensors are non-intersecting with one another.