A steel plate for linepipe excellent in sour resistance, collapse resistance, and low-temperature toughness wherein the linepipe has a 0.2% flow stress of compression in the circumferential direction after aging at 200°C of 450 MPa or more tested according to ASTM E9-09 and a crack length ratio of 10% or less, wherein the crack length ratio is determined by a HIC test based on TM0284 of the National Association of Corrosion and Engineer using as the test solution the Solution B, comprising: steel plate with a plate thickness of 25 mm to 45 mm consisting of, by mass%, C: 0.04 to 0.08%, Mn: 1.2 to 2.0%, Nb: 0.005 to 0.05%, Ti: 0.005 to 0.03%, Ca: 0.0005 to 0.0050%, N: 0.001 to 0.008%, and optionally, one or more of Cu: 0.50% or less, Ni: 0.50% or less, Cr: 0.50% or less, Mo: 0.50% or less, W: 0.50% or less, V: 0.10% or less, Zr: 0.050% or less, Ta: 0.050% or less, B: 0.0020% or less, Mg: 0.010% or less, REM: 0.0050% or less, Y: 0.0050% or less, Hf: 0.0050% or less, Re: 0.0050% or less, Si: 0.5% or less, Al: 0.05% or less, P: 0.03% or less, S: 0.005% or less, O: 0.005% or less, and having a balance of Fe and unavoidable impurities, wherein Sb, Sn, Co, and As can be contained in amounts of 0.1% or less, Pb and Bi in 0.005% or less, and H in 0.0005% or less as unavoidable impurities, and having a tensile strength of 500 to 700 MPa and a DWTT shear area at -10°C of 85% or more, a microstructure of surface layer portion which is portion from surface of the steel plate down toward a plate thickness direction by 0.9 mm to 1.1 mm is restricted to, by area percentage, deformed ferrite: 5% or more and S fel % found by the following formula la or less and martensite-austenite mixture: 0.1 to 8% or less and has a balance of one or both of polygonal ferrite and bainite, and a microstructure of a part from the center of plate thickness toward both the front and back sides of the steel plate by within 1 mm, constituting a mid-thickness portion, is restricted to, by area percentage, deformed ferrite: 5% or less, martensite-austenite mixture: 5% or less and has a balance of one or both of acicular ferrite and bainite, and the surface layer portion and mid-thickness portion have average value of effective grain size measured by electron backscatter diffraction of 20 μm or less, S fe 1 = 0.6552 × T H − 4.7826 where, T H: plate thickness of steel plate for linepipe. steel plate with a plate thickness of 25 mm to 45 mm consisting of, by mass%, C: 0.04 to 0.08%, Mn: 1.2 to 2.0%, Nb: 0.005 to 0.05%, Ti: 0.005 to 0.03%, Ca: 0.0005 to 0.0050%, N: 0.001 to 0.008%, and optionally, one or more of Cu: 0.50% or less, Ni: 0.50% or less, Cr: 0.50% or less, Mo: 0.50% or less, W: 0.50% or less, V: 0.10% or less, Zr: 0.050% or less, Ta: 0.050% or less, B: 0.0020% or less, Mg: 0.010% or less, REM: 0.0050% or less, Y: 0.0050% or less, Hf: 0.0050% or less, Re: 0.0050% or less, Si: 0.5% or less, Al: 0.05% or less, P: 0.03% or less, S: 0.005% or less, O: 0.005% or less, and having a balance of Fe and unavoidable impurities, wherein Sb, Sn, Co, and As can be contained in amounts of 0.1% or less, Pb and Bi in 0.005% or less, and H in 0.0005% or less as unavoidable impurities, and having a tensile strength of 500 to 700 MPa and a DWTT shear area at -10°C of 85% or more, a microstructure of surface layer portion which is portion from surface of the steel plate down toward a plate thickness direction by 0.9 mm to 1.1 mm is restricted to, by area percentage, deformed ferrite: 5% or more and S fel % found by the following formula la or less and martensite-austenite mixture: 0.1 to 8% or less and has a balance of one or both of polygonal ferrite and bainite, and a microstructure of a part from the center of plate thickness toward both the front and back sides of the steel plate by within 1 mm, constituting a mid-thickness portion, is restricted to, by area percentage, deformed ferrite: 5% or less, martensite-austenite mixture: 5% or less and has a balance of one or both of acicular ferrite and bainite, and the surface layer portion and mid-thickness portion have average value of effective grain size measured by electron backscatter diffraction of 20 μm or less, S fe 1 = 0.6552 × T H − 4.7826 where, T H: plate thickness of steel plate for linepipe.