To provide a blow molded item having an improved external appearance such as surface gloss and a method for blow-molding the same.

An air spoiler 17 being a blow-molded item comprises a polypropylene resin having a melt index(MI) in the range of from 0.01 g/10 min. to 10 g/10 min. and has a gloss value of 85% or more and variations in shrink and/or warpage of 1 mm or less. In the method for blow-molding the air spoiler 17, the surface temperature of a die 14 is held in the range from (crystallizing temperature of the resin -10°C)-(melting point of the resin) during the time while the die is clamped and opened to take out a blow-molded item, and the holding time at a maximum temperature is from 5.0 to less than 30 seconds, and in addition the temperature of the die is held at 90°C or lower when the die is opened to take out the spoiler 17.