Engine-powered portable working apparatus (100) including a soundproof casing (4) for accommodatingly supporting therein a main unit (1) having an engine (10) and a rotary working machine (11) driven by the engine, and a carrying handle (6) provided on the soundproof casing. The soundproof casing (4) comprises a first casing half (2) and a second casing half (3) to be joined together along a predetermined mating plane (P). The first and second casing halves (2, 3) are, respectively, integrally formed with a first handle half part (23) and a second handle half part (33) to be joined together along the mating plane (P) to thereby cooperate with each other to constitute the carrying handle (6). The working apparatus (100) further comprises an anti-vibratory member (5) for elastically holding the main unit (1) in the soundproof casing (4).