A vacuum cleaner with a dust collecting device (100, 200) comprising: a case (101, 201) forming an outer appearance of the dust collecting device (100, 200); a first cyclone (110, 210), installed within the case (101, 201), being configured to separate dust from air with foreign objects introduced from one side thereof and discharge the separated dust to a first dust storage unit (105, 205) through an outlet (111a, 211a) provided at an opposite side thereof; a plurality of second cyclones (120, 220), arranged along an inner surface of the case (101, 201), being configured to separate, from the air which has passed through the first cyclone (110, 210), finer dust that is not separated and discharge the separated finer dust to a second dust storage unit (106, 206); and a lower cover unit (130, 230) rotatably coupled to one side of the case (101, 201) by a hinge (131, 231) so as to form a bottom surface of the first dust storage unit (105, 205) and the second dust storage unit (106, 206), being configured to be rotatable by the hinge (131, 231) to simultaneously open/close the first dust storage unit (105, 205) and the second storage unit (106, 206) such that the collected dust and finer dust are simultaneously discharged, characterized in that the first cyclone (110, 210) comprises: a housing (111, 211), eccentric from the center of the case (101, 201), having said outlet (111a, 211a) formed thereon, at an upper portion, to communicate with the first dust storage unit (105, 205); and a mesh filter (112, 212), installed within the housing (111, 211) to extend parallel with the housing, for separating dust from air introduced to the interior of the housing (111, 211), wherein an inlet (191, 291) of the dust collecting device (100, 200) is formed on the lower cover unit (130, 230) to communicate with an internal space of the first cyclone (110, 210). a case (101, 201) forming an outer appearance of the dust collecting device (100, 200); a first cyclone (110, 210), installed within the case (101, 201), being configured to separate dust from air with foreign objects introduced from one side thereof and discharge the separated dust to a first dust storage unit (105, 205) through an outlet (111a, 211a) provided at an opposite side thereof; a plurality of second cyclones (120, 220), arranged along an inner surface of the case (101, 201), being configured to separate, from the air which has passed through the first cyclone (110, 210), finer dust that is not separated and discharge the separated finer dust to a second dust storage unit (106, 206); and a lower cover unit (130, 230) rotatably coupled to one side of the case (101, 201) by a hinge (131, 231) so as to form a bottom surface of the first dust storage unit (105, 205) and the second dust storage unit (106, 206), being configured to be rotatable by the hinge (131, 231) to simultaneously open/close the first dust storage unit (105, 205) and the second storage unit (106, 206) such that the collected dust and finer dust are simultaneously discharged, characterized in that the first cyclone (110, 210) comprises: a housing (111, 211), eccentric from the center of the case (101, 201), having said outlet (111a, 211a) formed thereon, at an upper portion, to communicate with the first dust storage unit (105, 205); and a mesh filter (112, 212), installed within the housing (111, 211) to extend parallel with the housing, for separating dust from air introduced to the interior of the housing (111, 211), wherein an inlet (191, 291) of the dust collecting device (100, 200) is formed on the lower cover unit (130, 230) to communicate with an internal space of the first cyclone (110, 210). a housing (111, 211), eccentric from the center of the case (101, 201), having said outlet (111a, 211a) formed thereon, at an upper portion, to communicate with the first dust storage unit (105, 205); and a mesh filter (112, 212), installed within the housing (111, 211) to extend parallel with the housing, for separating dust from air introduced to the interior of the housing (111, 211), wherein an inlet (191, 291) of the dust collecting device (100, 200) is formed on the lower cover unit (130, 230) to communicate with an internal space of the first cyclone (110, 210).