It is an object of the present invention to provide a stable production process for a melt-blown nonwoven fabric comprising thin fibers and having extremely few thick fibers [number of fusion-bonded fibers] formed by fusion bonding of thermoplastic resin fibers to one another, and an apparatus for the same. The present invention relates to a melt-blown nonwoven fabric comprising polyolefin fibers and having (i) a mean fiber diameter of not more than 2.0 μm, (ii) a fiber diameter distribution CV value of not more than 60%, and (iii) 15 or less fusion-bonded fibers based on 100 fibers; a production process for a melt-blown nonwoven fabric characterized by feeding cooling air of not higher than 30° C. from both side surfaces of outlets of slits 31 from which high-temperature high-velocity air is gushed out and thereby cooling the spun molten resin; and a production apparatus for the same.