A blood analyzer comprising: a flow cell configured to flow a measurement specimen containing blood cells; a first light source configured to emit light having a first wavelength, wherein the first light source is a semiconductor laser light source configured to irradiate light having the first wavelength of greater than or equal to 400 nm and smaller than or equal to 435 nm; a second light source configured to emit light having a second wavelength different from the first wavelength; wherein the second light source is a semiconductor laser light source configured to irradiate light having the second wavelength of greater than or equal to 610 nm and smaller than or equal to 750 nm; a first light receiving portion configured to receive first forward scattered light obtained by irradiating the blood cells passing through the flow cell with light from the first light source; a second light receiving portion configured to receive second forward scattered light obtained by irradiating the blood cells passing through the flow cell with light from the second light source; a display section configured to display an image; and a control section configured to: acquire detection signals output from the first light receiving portion and the second light receiving portion, respectively, for each of the blood cells flowing through the flow cell; discriminate red blood cells from the blood cells contained in the measurement specimen based on first detection signals output from the first light receiving portion and the second light receiving portion, respectively; discriminate white blood cells from the blood cells contained in the measurement specimen based on second detection signals output from the first light receiving portion and the second light receiving portion, respectively; wherein blood cells whose second detection signal output from the first light receiving portion is smaller than or equal to a predetermined threshold value are excluded from a target of analysis, wherein the second detection signals output from the first light receiving portion and the second light receiving portion, respectively, acquired from such excluded blood cells are not stored in a memory, and wherein the first detection signals are output during a first predetermined time and the second detection signals are output during a second predetermined time, the control section being further configured to: generate a scattergram having the intensity of the first forward scattered light and the intensity of the second forward scattered light as two axes based on the second detection signals output from the first light receiving portion and the second light receiving portion, respectively, display the generated scattergram on the display section, and sectionalize the white blood cells into lymphocytes, monocytes and granulocytes based on the difference of the distribution positions of the white blood cells in the generated scattergram. a flow cell configured to flow a measurement specimen containing blood cells; a first light source configured to emit light having a first wavelength, wherein the first light source is a semiconductor laser light source configured to irradiate light having the first wavelength of greater than or equal to 400 nm and smaller than or equal to 435 nm; a second light source configured to emit light having a second wavelength different from the first wavelength; wherein the second light source is a semiconductor laser light source configured to irradiate light having the second wavelength of greater than or equal to 610 nm and smaller than or equal to 750 nm; a first light receiving portion configured to receive first forward scattered light obtained by irradiating the blood cells passing through the flow cell with light from the first light source; a second light receiving portion configured to receive second forward scattered light obtained by irradiating the blood cells passing through the flow cell with light from the second light source; a display section configured to display an image; and acquire detection signals output from the first light receiving portion and the second light receiving portion, respectively, for each of the blood cells flowing through the flow cell; discriminate red blood cells from the blood cells contained in the measurement specimen based on first detection signals output from the first light receiving portion and the second light receiving portion, respectively; discriminate white blood cells from the blood cells contained in the measurement specimen based on second detection signals output from the first light receiving portion and the second light receiving portion, respectively; wherein blood cells whose second detection signal output from the first light receiving portion is smaller than or equal to a predetermined threshold value are excluded from a target of analysis, wherein the second detection signals output from the first light receiving portion and the second light receiving portion, respectively, acquired from such excluded blood cells are not stored in a memory, and generate a scattergram having the intensity of the first forward scattered light and the intensity of the second forward scattered light as two axes based on the second detection signals output from the first light receiving portion and the second light receiving portion, respectively, display the generated scattergram on the display section, and sectionalize the white blood cells into lymphocytes, monocytes and granulocytes based on the difference of the distribution positions of the white blood cells in the generated scattergram.