An LC type plug with a shutter configured to be fitted into an LC type adapter, the LC type plug comprising: a plug frame configured to retain a ferrule; a front housing arranged so as to be slidable on the plug frame; a shutter configured to open and close in association with a movement of the ferrule at a distal end side opening of the front housing; a locking housing fixedly and integrally connected to the plug frame; and a spring being provided between an upper part of the front housing and the locking housing, the spring being configured to bias the front housing forward, the front housing having: a square cylindrical body; a guide portion formed on an upper part of the square cylindrical body; and a front portion storage space formed in the guide portion, storing a front portion of the spring; and the locking housing having: a square cylindrical body; a rear portion storage space formed on an upper part of the square cylindrical body of the locking housing, and storing a rear portion of the spring; and a locking strip configured to be fitted into and locked with the LC type adapter, the LC type plug being characterized in that: the rear portion storage space stores a rear end side of the front portion storage space such that the spring is not exposed to an outside, and the entire part is stored in the both storage spaces (2c, 3a), even in a non-connected state of the plug; and the locking strip extends over the rear portion storage space. a plug frame configured to retain a ferrule; a front housing arranged so as to be slidable on the plug frame; a shutter configured to open and close in association with a movement of the ferrule at a distal end side opening of the front housing; a locking housing fixedly and integrally connected to the plug frame; and a spring being provided between an upper part of the front housing and the locking housing, the spring being configured to bias the front housing forward, the front housing having: a square cylindrical body; a guide portion formed on an upper part of the square cylindrical body; and a front portion storage space formed in the guide portion, storing a front portion of the spring; and the locking housing having: a square cylindrical body; a rear portion storage space formed on an upper part of the square cylindrical body of the locking housing, and storing a rear portion of the spring; and a locking strip configured to be fitted into and locked with the LC type adapter, the LC type plug being characterized in that: the rear portion storage space stores a rear end side of the front portion storage space such that the spring is not exposed to an outside, and the entire part is stored in the both storage spaces (2c, 3a), even in a non-connected state of the plug; and the locking strip extends over the rear portion storage space. a square cylindrical body; a guide portion formed on an upper part of the square cylindrical body; and a front portion storage space formed in the guide portion, storing a front portion of the spring; and the locking housing having: a square cylindrical body; a rear portion storage space formed on an upper part of the square cylindrical body of the locking housing, and storing a rear portion of the spring; and a locking strip configured to be fitted into and locked with the LC type adapter, the LC type plug being characterized in that: the rear portion storage space stores a rear end side of the front portion storage space such that the spring is not exposed to an outside, and the entire part is stored in the both storage spaces (2c, 3a), even in a non-connected state of the plug; and the locking strip extends over the rear portion storage space. a square cylindrical body; a rear portion storage space formed on an upper part of the square cylindrical body of the locking housing, and storing a rear portion of the spring; and a locking strip configured to be fitted into and locked with the LC type adapter, the LC type plug being characterized in that: the rear portion storage space stores a rear end side of the front portion storage space such that the spring is not exposed to an outside, and the entire part is stored in the both storage spaces (2c, 3a), even in a non-connected state of the plug; and the locking strip extends over the rear portion storage space. the rear portion storage space stores a rear end side of the front portion storage space such that the spring is not exposed to an outside, and the entire part is stored in the both storage spaces (2c, 3a), even in a non-connected state of the plug; and the locking strip extends over the rear portion storage space.