A low-emissivity glass which is outstandingly durable and is heat treatable without any changes in its characteristics before and after the heat treatment; and a production method therefor. The heat-treatable low-emissivity glass according to the present invention is characterized in that it comprises: a sunlight-adjusting metal layer which is formed above a glass substrate; a first dielectric layer which is formed below the sunlight-adjusting metal layer; a second dielectric layer which is formed above the sunlight-adjusting metal layer; and an uppermost protective layer which is formed above the second dielectric layer, and in that the first dielectric layer has a structure obtained by the lamination of a lowermost dielectric layer comprising a metal oxide and a lower metal protective dielectric layer comprising a metal (oxy)nitride, and an advantage of the present invention is that there is no change in the characteristics of the low-emissivity glass even after heat treatment.