A horn speaker having wide directional characteristics in accordance with the present invention provides a horn having a horn wall the shape of which is formed by connecting a plurality of curves having different flaring constants. The flaring constant of the curve forming a mouth portion of the horn wall is selected so as to be greater than that of the curve forming a throat portion thereof. The mouth portion of the horn wall is shaped so as to have a flaring angle which is formed by the curve at the mouth portion and has no abrupt variation of angle to a baffle plate. The curve at the mouth portion is connected with the curve at the horn wall nearer to the throat portion and having the flaring constant different therefrom at a point at which the differential coefficients of the respective curves substantially coincide with each other.
