Provided are a phosphor, a manufacture thereof, and an illuminating device and an image display device using same which has excellent blue excitation characteristics of at least 440 nm and not exceeding 449 nm. The phosphor of the present invention includes an inorganic compound in which an AlON crystal, an AlON solid solution crystal, or an inorganic crystal having a same crystal structure as AlON, includes at least Mn and an A element (where the A element is a monovalent metal element) and, if necessary, a D element (where the D element is an element other than Mn, the A element, Al, O, and N) wherein, upon irradiation of an excitation source, the phosphor emits fluorescence having a peak wavelength in a range of at least 490 nm and not exceeding 550 nm.