The object of the present invention is to improve the efficiency as a reduction gear by suppressing the deflection of the planetary gears to increase the rotation efficiency. The means to solve the problem is a deceleration device of an electric reel, which is a deceleration device (10) of an electric reel (1) that reduces the rotational driving force of a motor (4) and then transmits it to a reel. Equipped with: a sun gear (11) provided on the motor rotating shaft (41)； a plurality of planet gears (12) meshed with the sun gear (11) and having a planet gear support shaft； and coaxially arranged with the sun gear (11), An inner peripheral gear having an inner peripheral portion that meshes a plurality of planet gears (12), a ring gear (13) that moves the plurality of planet gears (12) around the inner peripheral gear； and supports the plurality of planet gears (12) The planetary gears support both ends of the shaft, and with the orbital movement of a plurality of planetary gears (12), rotate around the sun gear (11) to transmit the rotational driving force to the carrier (6) of the reel.本發明之課題係在於藉由抑制行星齒輪的偏轉，使旋轉效率提升，能夠提高作為減速裝置之效率。用以解決課題之手段為，一種電動捲線器的減速裝置，係將馬達(4)的旋轉驅動力減速後再傳達至捲筒之電動捲線器(1)的減速裝置(10)，其特徵為具備：設在馬達旋轉軸(41)之太陽齒輪(11)；嚙合於太陽齒輪(11)，並具有行星齒輪支承軸之複數個行星齒輪(12)；與太陽齒輪(11)同軸地設置，具有以內周部使複數個行星齒輪(12)嚙合之內周齒輪，沿著內周齒輪使複數個行星齒輪(12)環繞移動之環狀齒輪(13)；及支承複數個行星齒輪(12)的行星齒輪支承軸之兩端，並且伴隨複數個行星齒輪(12)的環繞移動，以太陽齒輪(11)為中心進行旋轉而將旋轉驅動力傳達至捲筒之載體(6)。
