A compass device comprising: a base seat having an accommodation hole which is bordered by an inner peripheral surface, and an orientation reading line; a vial unit including a vial housing which is received in said accommodation hole and spaced apart from said inner peripheral surface, a rotatable magnetic needle which is disposed in said vial housing, and an orientation aligning line and an orientation aligning arrow which are formed on said vial housing and below said magnetic needle; and an azimuth unit including a rotary sleeve member which is received in said accommodation hole and which is rotatably sleeved around said vial housing, and an azimuth ring which is retained on said rotary sleeve member and which surrounds said magnetic needle, said orientation aligning line and said orientation aligning arrow, characterized in that said compass device further comprises: a first spring wire interposed between said vial housing and said rotary sleeve member, said first spring wire being bent to form a plurality of first clamping sections which are wrapped on said vial housing and each of which extends radially and outwardly to connect with two adjacent ones of said first clamping sections at two first junctures that abut against said rotary sleeve member to resiliently retain said vial housing to said rotary sleeve member and to permit rotation of said vial housing relative to said azimuth unit and position at an angular position for magnetic declination adjustment; and a second spring wire interposed between said rotary sleeve member and said inner peripheral surface of said base seat, said second spring wire being bent to form a plurality of second clamping sections which are wrapped on said rotary sleeve member and each of which extends radially and outwardly to connect with two adjacent ones of said second clamping sections at two second junctures that abut against said inner peripheral surface of said base seat to resiliently retain said rotary sleeve member to said base seat and to permit rotation of said azimuth unit and said vial housing relative to said base seat and position at an angular position for bearing angle measurement. a base seat having an accommodation hole which is bordered by an inner peripheral surface, and an orientation reading line; a vial unit including a vial housing which is received in said accommodation hole and spaced apart from said inner peripheral surface, a rotatable magnetic needle which is disposed in said vial housing, and an orientation aligning line and an orientation aligning arrow which are formed on said vial housing and below said magnetic needle; and an azimuth unit including a rotary sleeve member which is received in said accommodation hole and which is rotatably sleeved around said vial housing, and an azimuth ring which is retained on said rotary sleeve member and which surrounds said magnetic needle, said orientation aligning line and said orientation aligning arrow, characterized in that said compass device further comprises: a first spring wire interposed between said vial housing and said rotary sleeve member, said first spring wire being bent to form a plurality of first clamping sections which are wrapped on said vial housing and each of which extends radially and outwardly to connect with two adjacent ones of said first clamping sections at two first junctures that abut against said rotary sleeve member to resiliently retain said vial housing to said rotary sleeve member and to permit rotation of said vial housing relative to said azimuth unit and position at an angular position for magnetic declination adjustment; and a second spring wire interposed between said rotary sleeve member and said inner peripheral surface of said base seat, said second spring wire being bent to form a plurality of second clamping sections which are wrapped on said rotary sleeve member and each of which extends radially and outwardly to connect with two adjacent ones of said second clamping sections at two second junctures that abut against said inner peripheral surface of said base seat to resiliently retain said rotary sleeve member to said base seat and to permit rotation of said azimuth unit and said vial housing relative to said base seat and position at an angular position for bearing angle measurement. a first spring wire interposed between said vial housing and said rotary sleeve member, said first spring wire being bent to form a plurality of first clamping sections which are wrapped on said vial housing and each of which extends radially and outwardly to connect with two adjacent ones of said first clamping sections at two first junctures that abut against said rotary sleeve member to resiliently retain said vial housing to said rotary sleeve member and to permit rotation of said vial housing relative to said azimuth unit and position at an angular position for magnetic declination adjustment; and a second spring wire interposed between said rotary sleeve member and said inner peripheral surface of said base seat, said second spring wire being bent to form a plurality of second clamping sections which are wrapped on said rotary sleeve member and each of which extends radially and outwardly to connect with two adjacent ones of said second clamping sections at two second junctures that abut against said inner peripheral surface of said base seat to resiliently retain said rotary sleeve member to said base seat and to permit rotation of said azimuth unit and said vial housing relative to said base seat and position at an angular position for bearing angle measurement.