A fluorescent-image acquisition apparatus comprising: an excitement-light source for radiating excitement light to a fluorescent marker on a biological sample; a dark-field radiation system; an objective lens for enlarging an image of a member of said biological sample, wherein said objective lens includes a first objective lens, a second objective lens and a dichroic mirror provided between the first objective lens and the second objective lens such that the excitement light propagates to the first objective lens after being reflected by said dichroic mirror, said first lens focusing the excitement light on said biological sample; an image pickup device for forming said member image enlarged by said objective lens to appear as a fluorescent image of said member; focal-point movement control means (11, 42) for moving the focal point of said objective lens in the thickness direction of said biological sample; and image-pickup control means for exposing said image pickup device to light and acquiring said member image enlarged by said objective lens to appear as said fluorescent image of said member from said image pickup device while said focal point of said objective lens is being moved in said thickness direction of said biological sample, said fluorescent-image acquisition apparatus being characterized in that said image-pickup control means is configured to start said light exposure of the image pickup device at a point of time the movement of said focal point is commenced and to terminate said light exposure at a point of time the movement of said focal point is ended, and in that the fluorescent-image acquisition apparatus is configured to transfer said fluorescent image from said image pickup device to the image-pickup control means at the point of time the movement of said focal point is ended. an excitement-light source for radiating excitement light to a fluorescent marker on a biological sample; a dark-field radiation system; an objective lens for enlarging an image of a member of said biological sample, wherein said objective lens includes a first objective lens, a second objective lens and a dichroic mirror provided between the first objective lens and the second objective lens such that the excitement light propagates to the first objective lens after being reflected by said dichroic mirror, said first lens focusing the excitement light on said biological sample; an image pickup device for forming said member image enlarged by said objective lens to appear as a fluorescent image of said member; focal-point movement control means (11, 42) for moving the focal point of said objective lens in the thickness direction of said biological sample; and image-pickup control means for exposing said image pickup device to light and acquiring said member image enlarged by said objective lens to appear as said fluorescent image of said member from said image pickup device while said focal point of said objective lens is being moved in said thickness direction of said biological sample, said fluorescent-image acquisition apparatus being characterized in that said image-pickup control means is configured to start said light exposure of the image pickup device at a point of time the movement of said focal point is commenced and to terminate said light exposure at a point of time the movement of said focal point is ended, and in that the fluorescent-image acquisition apparatus is configured to transfer said fluorescent image from said image pickup device to the image-pickup control means at the point of time the movement of said focal point is ended.