An earplug with enhanced wearing comfortability, comprising: a main guide body (20, 20'), provided with a guide portion (21, 21'), a compression portion (22, 22') that extends from the guide portion (21, 21'), and a stop portion (23, 23') that extends from the compression portion (22, 22'), wherein a connecting cavity (24, 24') is provided inside the guide portion (21, 21'), a filling cavity (25, 25') is provided inside the compression portion (22, 22'), and an opening portion (26, 26') is provided inside the stop portion (23, 23'); moreover, the filling cavity (25, 25') interconnects the connecting cavity (24, 24') and the opening portion (26, 26'); a supporting stem (30, 30'), which is provided with a connecting section (31, 31') that enables embedding into the connecting cavity (24, 24'), an extended section (32, 32') that extends from the connecting section (31, 31') and is positioned inside the filling cavity (25, 25'), and a securing section (33, 33') that extends from the extended section (32, 32') and embeds within the opening portion (26, 26'); moreover, the securing section (33, 33') is provided with an air passage (34, 34'), which enables air to pass therethrough from an exterior of the main guide body (20, 20') and circulate to an interior of the filling cavity (25, 25'); and a filler material (40, 40') provided with plasticity, which fills the interior of the filling cavity (25, 25') and causes an air chamber (27, 27') to form therein and contain air, such that, air enters the air chamber (27, 27') through the air passage (34, 34') and cause the compression portion (22, 22') to form its original state; whereby when the compression portion (22, 22') is pressed and constricted, the compression portion (22, 22') compresses the air within the air chamber (27, 27') through the filler material (40, 40'), thereby expelling the air through the air passage (34, 34') and causing the compression portion (22, 22') to form a compressed state; and after releasing the pressure on the compression portion (22, 22'), air enters the air chamber (27, 27') through the air passage (34, 34') and squeezes the filler material (40, 40'), thereby causing the compression portion (22, 22') to return to an original state from a compressed state. a main guide body (20, 20'), provided with a guide portion (21, 21'), a compression portion (22, 22') that extends from the guide portion (21, 21'), and a stop portion (23, 23') that extends from the compression portion (22, 22'), wherein a connecting cavity (24, 24') is provided inside the guide portion (21, 21'), a filling cavity (25, 25') is provided inside the compression portion (22, 22'), and an opening portion (26, 26') is provided inside the stop portion (23, 23'); moreover, the filling cavity (25, 25') interconnects the connecting cavity (24, 24') and the opening portion (26, 26'); a supporting stem (30, 30'), which is provided with a connecting section (31, 31') that enables embedding into the connecting cavity (24, 24'), an extended section (32, 32') that extends from the connecting section (31, 31') and is positioned inside the filling cavity (25, 25'), and a securing section (33, 33') that extends from the extended section (32, 32') and embeds within the opening portion (26, 26'); moreover, the securing section (33, 33') is provided with an air passage (34, 34'), which enables air to pass therethrough from an exterior of the main guide body (20, 20') and circulate to an interior of the filling cavity (25, 25'); and a filler material (40, 40') provided with plasticity, which fills the interior of the filling cavity (25, 25') and causes an air chamber (27, 27') to form therein and contain air, such that, air enters the air chamber (27, 27') through the air passage (34, 34') and cause the compression portion (22, 22') to form its original state; whereby when the compression portion (22, 22') is pressed and constricted, the compression portion (22, 22') compresses the air within the air chamber (27, 27') through the filler material (40, 40'), thereby expelling the air through the air passage (34, 34') and causing the compression portion (22, 22') to form a compressed state; and after releasing the pressure on the compression portion (22, 22'), air enters the air chamber (27, 27') through the air passage (34, 34') and squeezes the filler material (40, 40'), thereby causing the compression portion (22, 22') to return to an original state from a compressed state.